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

   1 // This file is Copyright its original authors, visible in version control
   2 // history.
   3 //
   4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
   5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
   7 // You may not use this file except in accordance with one or both of these
   8 // licenses.
   9
  10 //! Events are returned from various bits in the library which indicate some action must be taken
  11 //! by the client.
  12 //!
  13 //! Because we don't have a built-in runtime, it's up to the client to call events at a time in the
  14 //! future, as well as generate and broadcast funding transactions handle payment preimages and a
  15 //! few other things.
  16
  17 #[cfg(anchors)]
  18 pub mod bump_transaction;
  19
  20 #[cfg(anchors)]
  21 pub use bump_transaction::BumpTransactionEvent;
  22
  23 use crate::chain::keysinterface::SpendableOutputDescriptor;
  24 use crate::ln::channelmanager::{InterceptId, PaymentId, RecipientOnionFields};
  25 use crate::ln::channel::FUNDING_CONF_DEADLINE_BLOCKS;
  26 use crate::ln::features::ChannelTypeFeatures;
  27 use crate::ln::msgs;
  28 use crate::ln::{PaymentPreimage, PaymentHash, PaymentSecret};
  29 use crate::routing::gossip::NetworkUpdate;
  30 use crate::util::errors::APIError;
  31 use crate::util::ser::{BigSize, FixedLengthReader, Writeable, Writer, MaybeReadable, Readable, RequiredWrapper, UpgradableRequired, WithoutLength};
  32 use crate::util::string::UntrustedString;
  33 use crate::routing::router::{BlindedTail, Path, RouteHop, RouteParameters};
  34
  35 use bitcoin::{PackedLockTime, Transaction, OutPoint};
  36 #[cfg(anchors)]
  37 use bitcoin::{Txid, TxIn, TxOut, Witness};
  38 use bitcoin::blockdata::script::Script;
  39 use bitcoin::hashes::Hash;
  40 use bitcoin::hashes::sha256::Hash as Sha256;
  41 use bitcoin::secp256k1::PublicKey;
  42 use crate::io;
  43 use crate::prelude::*;
  44 use core::time::Duration;
  45 use core::ops::Deref;
  46 use crate::sync::Arc;
  47
  48 /// Some information provided on receipt of payment depends on whether the payment received is a
  49 /// spontaneous payment or a "conventional" lightning payment that's paying an invoice.
  50 #[derive(Clone, Debug, PartialEq, Eq)]
  51 pub enum PaymentPurpose {
  52         /// Information for receiving a payment that we generated an invoice for.
  53         InvoicePayment {
  54                 /// The preimage to the payment_hash, if the payment hash (and secret) were fetched via
  55                 /// [`ChannelManager::create_inbound_payment`]. If provided, this can be handed directly to
  56                 /// [`ChannelManager::claim_funds`].
  57                 ///
  58                 /// [`ChannelManager::create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
  59                 /// [`ChannelManager::claim_funds`]: crate::ln::channelmanager::ChannelManager::claim_funds
  60                 payment_preimage: Option<PaymentPreimage>,
  61                 /// The "payment secret". This authenticates the sender to the recipient, preventing a
  62                 /// number of deanonymization attacks during the routing process.
  63                 /// It is provided here for your reference, however its accuracy is enforced directly by
  64                 /// [`ChannelManager`] using the values you previously provided to
  65                 /// [`ChannelManager::create_inbound_payment`] or
  66                 /// [`ChannelManager::create_inbound_payment_for_hash`].
  67                 ///
  68                 /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
  69                 /// [`ChannelManager::create_inbound_payment`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment
  70                 /// [`ChannelManager::create_inbound_payment_for_hash`]: crate::ln::channelmanager::ChannelManager::create_inbound_payment_for_hash
  71                 payment_secret: PaymentSecret,
  72         },
  73         /// Because this is a spontaneous payment, the payer generated their own preimage rather than us
  74         /// (the payee) providing a preimage.
  75         SpontaneousPayment(PaymentPreimage),
  76 }
  77
  78 impl_writeable_tlv_based_enum!(PaymentPurpose,
  79         (0, InvoicePayment) => {
  80                 (0, payment_preimage, option),
  81                 (2, payment_secret, required),
  82         };
  83         (2, SpontaneousPayment)
  84 );
  85
  86 /// When the payment path failure took place and extra details about it. [`PathFailure::OnPath`] may
  87 /// contain a [`NetworkUpdate`] that needs to be applied to the [`NetworkGraph`].
  88 ///
  89 /// [`NetworkUpdate`]: crate::routing::gossip::NetworkUpdate
  90 /// [`NetworkGraph`]: crate::routing::gossip::NetworkGraph
  91 #[derive(Clone, Debug, Eq, PartialEq)]
  92 pub enum PathFailure {
  93         /// We failed to initially send the payment and no HTLC was committed to. Contains the relevant
  94         /// error.
  95         InitialSend {
  96                 /// The error surfaced from initial send.
  97                 err: APIError,
  98         },
  99         /// A hop on the path failed to forward our payment.
 100         OnPath {
 101                 /// If present, this [`NetworkUpdate`] should be applied to the [`NetworkGraph`] so that routing
 102                 /// decisions can take into account the update.
 103                 ///
 104                 /// [`NetworkUpdate`]: crate::routing::gossip::NetworkUpdate
 105                 /// [`NetworkGraph`]: crate::routing::gossip::NetworkGraph
 106                 network_update: Option<NetworkUpdate>,
 107         },
 108 }
 109
 110 impl_writeable_tlv_based_enum_upgradable!(PathFailure,
 111         (0, OnPath) => {
 112                 (0, network_update, upgradable_option),
 113         },
 114         (2, InitialSend) => {
 115                 (0, err, upgradable_required),
 116         },
 117 );
 118
 119 #[derive(Clone, Debug, PartialEq, Eq)]
 120 /// The reason the channel was closed. See individual variants more details.
 121 pub enum ClosureReason {
 122         /// Closure generated from receiving a peer error message.
 123         ///
 124         /// Our counterparty may have broadcasted their latest commitment state, and we have
 125         /// as well.
 126         CounterpartyForceClosed {
 127                 /// The error which the peer sent us.
 128                 ///
 129                 /// Be careful about printing the peer_msg, a well-crafted message could exploit
 130                 /// a security vulnerability in the terminal emulator or the logging subsystem.
 131                 /// To be safe, use `Display` on `UntrustedString`
 132                 ///
 133                 /// [`UntrustedString`]: crate::util::string::UntrustedString
 134                 peer_msg: UntrustedString,
 135         },
 136         /// Closure generated from [`ChannelManager::force_close_channel`], called by the user.
 137         ///
 138         /// [`ChannelManager::force_close_channel`]: crate::ln::channelmanager::ChannelManager::force_close_channel.
 139         HolderForceClosed,
 140         /// The channel was closed after negotiating a cooperative close and we've now broadcasted
 141         /// the cooperative close transaction. Note the shutdown may have been initiated by us.
 142         //TODO: split between CounterpartyInitiated/LocallyInitiated
 143         CooperativeClosure,
 144         /// A commitment transaction was confirmed on chain, closing the channel. Most likely this
 145         /// commitment transaction came from our counterparty, but it may also have come from
 146         /// a copy of our own `ChannelMonitor`.
 147         CommitmentTxConfirmed,
 148         /// The funding transaction failed to confirm in a timely manner on an inbound channel.
 149         FundingTimedOut,
 150         /// Closure generated from processing an event, likely a HTLC forward/relay/reception.
 151         ProcessingError {
 152                 /// A developer-readable error message which we generated.
 153                 err: String,
 154         },
 155         /// The peer disconnected prior to funding completing. In this case the spec mandates that we
 156         /// forget the channel entirely - we can attempt again if the peer reconnects.
 157         ///
 158         /// This includes cases where we restarted prior to funding completion, including prior to the
 159         /// initial [`ChannelMonitor`] persistence completing.
 160         ///
 161         /// In LDK versions prior to 0.0.107 this could also occur if we were unable to connect to the
 162         /// peer because of mutual incompatibility between us and our channel counterparty.
 163         ///
 164         /// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
 165         DisconnectedPeer,
 166         /// Closure generated from `ChannelManager::read` if the [`ChannelMonitor`] is newer than
 167         /// the [`ChannelManager`] deserialized.
 168         ///
 169         /// [`ChannelMonitor`]: crate::chain::channelmonitor::ChannelMonitor
 170         /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
 171         OutdatedChannelManager
 172 }
 173
 174 impl core::fmt::Display for ClosureReason {
 175         fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
 176                 f.write_str("Channel closed because ")?;
 177                 match self {
 178                         ClosureReason::CounterpartyForceClosed { peer_msg } => {
 179                                 f.write_fmt(format_args!("counterparty force-closed with message: {}", peer_msg))
 180                         },
 181                         ClosureReason::HolderForceClosed => f.write_str("user manually force-closed the channel"),
 182                         ClosureReason::CooperativeClosure => f.write_str("the channel was cooperatively closed"),
 183                         ClosureReason::CommitmentTxConfirmed => f.write_str("commitment or closing transaction was confirmed on chain."),
 184                         ClosureReason::FundingTimedOut => write!(f, "funding transaction failed to confirm within {} blocks", FUNDING_CONF_DEADLINE_BLOCKS),
 185                         ClosureReason::ProcessingError { err } => {
 186                                 f.write_str("of an exception: ")?;
 187                                 f.write_str(&err)
 188                         },
 189                         ClosureReason::DisconnectedPeer => f.write_str("the peer disconnected prior to the channel being funded"),
 190                         ClosureReason::OutdatedChannelManager => f.write_str("the ChannelManager read from disk was stale compared to ChannelMonitor(s)"),
 191                 }
 192         }
 193 }
 194
 195 impl_writeable_tlv_based_enum_upgradable!(ClosureReason,
 196         (0, CounterpartyForceClosed) => { (1, peer_msg, required) },
 197         (1, FundingTimedOut) => {},
 198         (2, HolderForceClosed) => {},
 199         (6, CommitmentTxConfirmed) => {},
 200         (4, CooperativeClosure) => {},
 201         (8, ProcessingError) => { (1, err, required) },
 202         (10, DisconnectedPeer) => {},
 203         (12, OutdatedChannelManager) => {},
 204 );
 205
 206 /// Intended destination of a failed HTLC as indicated in [`Event::HTLCHandlingFailed`].
 207 #[derive(Clone, Debug, PartialEq, Eq)]
 208 pub enum HTLCDestination {
 209         /// We tried forwarding to a channel but failed to do so. An example of such an instance is when
 210         /// there is insufficient capacity in our outbound channel.
 211         NextHopChannel {
 212                 /// The `node_id` of the next node. For backwards compatibility, this field is
 213                 /// marked as optional, versions prior to 0.0.110 may not always be able to provide
 214                 /// counterparty node information.
 215                 node_id: Option<PublicKey>,
 216                 /// The outgoing `channel_id` between us and the next node.
 217                 channel_id: [u8; 32],
 218         },
 219         /// Scenario where we are unsure of the next node to forward the HTLC to.
 220         UnknownNextHop {
 221                 /// Short channel id we are requesting to forward an HTLC to.
 222                 requested_forward_scid: u64,
 223         },
 224         /// We couldn't forward to the outgoing scid. An example would be attempting to send a duplicate
 225         /// intercept HTLC.
 226         InvalidForward {
 227                 /// Short channel id we are requesting to forward an HTLC to.
 228                 requested_forward_scid: u64
 229         },
 230         /// Failure scenario where an HTLC may have been forwarded to be intended for us,
 231         /// but is invalid for some reason, so we reject it.
 232         ///
 233         /// Some of the reasons may include:
 234         /// * HTLC Timeouts
 235         /// * Excess HTLCs for a payment that we have already fully received, over-paying for the
 236         ///   payment,
 237         /// * The counterparty node modified the HTLC in transit,
 238         /// * A probing attack where an intermediary node is trying to detect if we are the ultimate
 239         ///   recipient for a payment.
 240         FailedPayment {
 241                 /// The payment hash of the payment we attempted to process.
 242                 payment_hash: PaymentHash
 243         },
 244 }
 245
 246 impl_writeable_tlv_based_enum_upgradable!(HTLCDestination,
 247         (0, NextHopChannel) => {
 248                 (0, node_id, required),
 249                 (2, channel_id, required),
 250         },
 251         (1, InvalidForward) => {
 252                 (0, requested_forward_scid, required),
 253         },
 254         (2, UnknownNextHop) => {
 255                 (0, requested_forward_scid, required),
 256         },
 257         (4, FailedPayment) => {
 258                 (0, payment_hash, required),
 259         },
 260 );
 261
 262 /// Will be used in [`Event::HTLCIntercepted`] to identify the next hop in the HTLC's path.
 263 /// Currently only used in serialization for the sake of maintaining compatibility. More variants
 264 /// will be added for general-purpose HTLC forward intercepts as well as trampoline forward
 265 /// intercepts in upcoming work.
 266 enum InterceptNextHop {
 267         FakeScid {
 268                 requested_next_hop_scid: u64,
 269         },
 270 }
 271
 272 impl_writeable_tlv_based_enum!(InterceptNextHop,
 273         (0, FakeScid) => {
 274                 (0, requested_next_hop_scid, required),
 275         };
 276 );
 277
 278 /// The reason the payment failed. Used in [`Event::PaymentFailed`].
 279 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
 280 pub enum PaymentFailureReason {
 281         /// The intended recipient rejected our payment.
 282         RecipientRejected,
 283         /// The user chose to abandon this payment by calling [`ChannelManager::abandon_payment`].
 284         ///
 285         /// [`ChannelManager::abandon_payment`]: crate::ln::channelmanager::ChannelManager::abandon_payment
 286         UserAbandoned,
 287         /// We exhausted all of our retry attempts while trying to send the payment, or we
 288         /// exhausted the [`Retry::Timeout`] if the user set one. If at any point a retry
 289         /// attempt failed while being forwarded along the path, an [`Event::PaymentPathFailed`] will
 290         /// have come before this.
 291         ///
 292         /// [`Retry::Timeout`]: crate::ln::channelmanager::Retry::Timeout
 293         RetriesExhausted,
 294         /// The payment expired while retrying, based on the provided
 295         /// [`PaymentParameters::expiry_time`].
 296         ///
 297         /// [`PaymentParameters::expiry_time`]: crate::routing::router::PaymentParameters::expiry_time
 298         PaymentExpired,
 299         /// We failed to find a route while retrying the payment.
 300         RouteNotFound,
 301         /// This error should generally never happen. This likely means that there is a problem with
 302         /// your router.
 303         UnexpectedError,
 304 }
 305
 306 impl_writeable_tlv_based_enum!(PaymentFailureReason,
 307         (0, RecipientRejected) => {},
 308         (2, UserAbandoned) => {},
 309         (4, RetriesExhausted) => {},
 310         (6, PaymentExpired) => {},
 311         (8, RouteNotFound) => {},
 312         (10, UnexpectedError) => {}, ;
 313 );
 314
 315 /// An Event which you should probably take some action in response to.
 316 ///
 317 /// Note that while Writeable and Readable are implemented for Event, you probably shouldn't use
 318 /// them directly as they don't round-trip exactly (for example FundingGenerationReady is never
 319 /// written as it makes no sense to respond to it after reconnecting to peers).
 320 #[derive(Clone, Debug, PartialEq, Eq)]
 321 pub enum Event {
 322         /// Used to indicate that the client should generate a funding transaction with the given
 323         /// parameters and then call [`ChannelManager::funding_transaction_generated`].
 324         /// Generated in [`ChannelManager`] message handling.
 325         /// Note that *all inputs* in the funding transaction must spend SegWit outputs or your
 326         /// counterparty can steal your funds!
 327         ///
 328         /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
 329         /// [`ChannelManager::funding_transaction_generated`]: crate::ln::channelmanager::ChannelManager::funding_transaction_generated
 330         FundingGenerationReady {
 331                 /// The random channel_id we picked which you'll need to pass into
 332                 /// [`ChannelManager::funding_transaction_generated`].
 333                 ///
 334                 /// [`ChannelManager::funding_transaction_generated`]: crate::ln::channelmanager::ChannelManager::funding_transaction_generated
 335                 temporary_channel_id: [u8; 32],
 336                 /// The counterparty's node_id, which you'll need to pass back into
 337                 /// [`ChannelManager::funding_transaction_generated`].
 338                 ///
 339                 /// [`ChannelManager::funding_transaction_generated`]: crate::ln::channelmanager::ChannelManager::funding_transaction_generated
 340                 counterparty_node_id: PublicKey,
 341                 /// The value, in satoshis, that the output should have.
 342                 channel_value_satoshis: u64,
 343                 /// The script which should be used in the transaction output.
 344                 output_script: Script,
 345                 /// The `user_channel_id` value passed in to [`ChannelManager::create_channel`], or a
 346                 /// random value for an inbound channel. This may be zero for objects serialized with LDK
 347                 /// versions prior to 0.0.113.
 348                 ///
 349                 /// [`ChannelManager::create_channel`]: crate::ln::channelmanager::ChannelManager::create_channel
 350                 user_channel_id: u128,
 351         },
 352         /// Indicates that we've been offered a payment and it needs to be claimed via calling
 353         /// [`ChannelManager::claim_funds`] with the preimage given in [`PaymentPurpose`].
 354         ///
 355         /// Note that if the preimage is not known, you should call
 356         /// [`ChannelManager::fail_htlc_backwards`] or [`ChannelManager::fail_htlc_backwards_with_reason`]
 357         /// to free up resources for this HTLC and avoid network congestion.
 358         /// If you fail to call either [`ChannelManager::claim_funds`], [`ChannelManager::fail_htlc_backwards`],
 359         /// or [`ChannelManager::fail_htlc_backwards_with_reason`] within the HTLC's timeout, the HTLC will be
 360         /// automatically failed.
 361         ///
 362         /// # Note
 363         /// LDK will not stop an inbound payment from being paid multiple times, so multiple
 364         /// `PaymentClaimable` events may be generated for the same payment. In such a case it is
 365         /// polite (and required in the lightning specification) to fail the payment the second time
 366         /// and give the sender their money back rather than accepting double payment.
 367         ///
 368         /// # Note
 369         /// This event used to be called `PaymentReceived` in LDK versions 0.0.112 and earlier.
 370         ///
 371         /// [`ChannelManager::claim_funds`]: crate::ln::channelmanager::ChannelManager::claim_funds
 372         /// [`ChannelManager::fail_htlc_backwards`]: crate::ln::channelmanager::ChannelManager::fail_htlc_backwards
 373         /// [`ChannelManager::fail_htlc_backwards_with_reason`]: crate::ln::channelmanager::ChannelManager::fail_htlc_backwards_with_reason
 374         PaymentClaimable {
 375                 /// The node that will receive the payment after it has been claimed.
 376                 /// This is useful to identify payments received via [phantom nodes].
 377                 /// This field will always be filled in when the event was generated by LDK versions
 378                 /// 0.0.113 and above.
 379                 ///
 380                 /// [phantom nodes]: crate::chain::keysinterface::PhantomKeysManager
 381                 receiver_node_id: Option<PublicKey>,
 382                 /// The hash for which the preimage should be handed to the ChannelManager. Note that LDK will
 383                 /// not stop you from registering duplicate payment hashes for inbound payments.
 384                 payment_hash: PaymentHash,
 385                 /// The fields in the onion which were received with each HTLC. Only fields which were
 386                 /// identical in each HTLC involved in the payment will be included here.
 387                 ///
 388                 /// Payments received on LDK versions prior to 0.0.115 will have this field unset.
 389                 onion_fields: Option<RecipientOnionFields>,
 390                 /// The value, in thousandths of a satoshi, that this payment is for.
 391                 amount_msat: u64,
 392                 /// Information for claiming this received payment, based on whether the purpose of the
 393                 /// payment is to pay an invoice or to send a spontaneous payment.
 394                 purpose: PaymentPurpose,
 395                 /// The `channel_id` indicating over which channel we received the payment.
 396                 via_channel_id: Option<[u8; 32]>,
 397                 /// The `user_channel_id` indicating over which channel we received the payment.
 398                 via_user_channel_id: Option<u128>,
 399                 /// The block height at which this payment will be failed back and will no longer be
 400                 /// eligible for claiming.
 401                 ///
 402                 /// Prior to this height, a call to [`ChannelManager::claim_funds`] is guaranteed to
 403                 /// succeed, however you should wait for [`Event::PaymentClaimed`] to be sure.
 404                 ///
 405                 /// [`ChannelManager::claim_funds`]: crate::ln::channelmanager::ChannelManager::claim_funds
 406                 claim_deadline: Option<u32>,
 407         },
 408         /// Indicates a payment has been claimed and we've received money!
 409         ///
 410         /// This most likely occurs when [`ChannelManager::claim_funds`] has been called in response
 411         /// to an [`Event::PaymentClaimable`]. However, if we previously crashed during a
 412         /// [`ChannelManager::claim_funds`] call you may see this event without a corresponding
 413         /// [`Event::PaymentClaimable`] event.
 414         ///
 415         /// # Note
 416         /// LDK will not stop an inbound payment from being paid multiple times, so multiple
 417         /// `PaymentClaimable` events may be generated for the same payment. If you then call
 418         /// [`ChannelManager::claim_funds`] twice for the same [`Event::PaymentClaimable`] you may get
 419         /// multiple `PaymentClaimed` events.
 420         ///
 421         /// [`ChannelManager::claim_funds`]: crate::ln::channelmanager::ChannelManager::claim_funds
 422         PaymentClaimed {
 423                 /// The node that received the payment.
 424                 /// This is useful to identify payments which were received via [phantom nodes].
 425                 /// This field will always be filled in when the event was generated by LDK versions
 426                 /// 0.0.113 and above.
 427                 ///
 428                 /// [phantom nodes]: crate::chain::keysinterface::PhantomKeysManager
 429                 receiver_node_id: Option<PublicKey>,
 430                 /// The payment hash of the claimed payment. Note that LDK will not stop you from
 431                 /// registering duplicate payment hashes for inbound payments.
 432                 payment_hash: PaymentHash,
 433                 /// The value, in thousandths of a satoshi, that this payment is for.
 434                 amount_msat: u64,
 435                 /// The purpose of the claimed payment, i.e. whether the payment was for an invoice or a
 436                 /// spontaneous payment.
 437                 purpose: PaymentPurpose,
 438         },
 439         /// Indicates an outbound payment we made succeeded (i.e. it made it all the way to its target
 440         /// and we got back the payment preimage for it).
 441         ///
 442         /// Note for MPP payments: in rare cases, this event may be preceded by a `PaymentPathFailed`
 443         /// event. In this situation, you SHOULD treat this payment as having succeeded.
 444         PaymentSent {
 445                 /// The `payment_id` passed to [`ChannelManager::send_payment`].
 446                 ///
 447                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 448                 payment_id: Option<PaymentId>,
 449                 /// The preimage to the hash given to ChannelManager::send_payment.
 450                 /// Note that this serves as a payment receipt, if you wish to have such a thing, you must
 451                 /// store it somehow!
 452                 payment_preimage: PaymentPreimage,
 453                 /// The hash that was given to [`ChannelManager::send_payment`].
 454                 ///
 455                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 456                 payment_hash: PaymentHash,
 457                 /// The total fee which was spent at intermediate hops in this payment, across all paths.
 458                 ///
 459                 /// Note that, like [`Route::get_total_fees`] this does *not* include any potential
 460                 /// overpayment to the recipient node.
 461                 ///
 462                 /// If the recipient or an intermediate node misbehaves and gives us free money, this may
 463                 /// overstate the amount paid, though this is unlikely.
 464                 ///
 465                 /// [`Route::get_total_fees`]: crate::routing::router::Route::get_total_fees
 466                 fee_paid_msat: Option<u64>,
 467         },
 468         /// Indicates an outbound payment failed. Individual [`Event::PaymentPathFailed`] events
 469         /// provide failure information for each path attempt in the payment, including retries.
 470         ///
 471         /// This event is provided once there are no further pending HTLCs for the payment and the
 472         /// payment is no longer retryable, due either to the [`Retry`] provided or
 473         /// [`ChannelManager::abandon_payment`] having been called for the corresponding payment.
 474         ///
 475         /// [`Retry`]: crate::ln::channelmanager::Retry
 476         /// [`ChannelManager::abandon_payment`]: crate::ln::channelmanager::ChannelManager::abandon_payment
 477         PaymentFailed {
 478                 /// The `payment_id` passed to [`ChannelManager::send_payment`].
 479                 ///
 480                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 481                 payment_id: PaymentId,
 482                 /// The hash that was given to [`ChannelManager::send_payment`].
 483                 ///
 484                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 485                 payment_hash: PaymentHash,
 486                 /// The reason the payment failed. This is only `None` for events generated or serialized
 487                 /// by versions prior to 0.0.115.
 488                 reason: Option<PaymentFailureReason>,
 489         },
 490         /// Indicates that a path for an outbound payment was successful.
 491         ///
 492         /// Always generated after [`Event::PaymentSent`] and thus useful for scoring channels. See
 493         /// [`Event::PaymentSent`] for obtaining the payment preimage.
 494         PaymentPathSuccessful {
 495                 /// The `payment_id` passed to [`ChannelManager::send_payment`].
 496                 ///
 497                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 498                 payment_id: PaymentId,
 499                 /// The hash that was given to [`ChannelManager::send_payment`].
 500                 ///
 501                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 502                 payment_hash: Option<PaymentHash>,
 503                 /// The payment path that was successful.
 504                 ///
 505                 /// May contain a closed channel if the HTLC sent along the path was fulfilled on chain.
 506                 path: Path,
 507         },
 508         /// Indicates an outbound HTLC we sent failed, likely due to an intermediary node being unable to
 509         /// handle the HTLC.
 510         ///
 511         /// Note that this does *not* indicate that all paths for an MPP payment have failed, see
 512         /// [`Event::PaymentFailed`].
 513         ///
 514         /// See [`ChannelManager::abandon_payment`] for giving up on this payment before its retries have
 515         /// been exhausted.
 516         ///
 517         /// [`ChannelManager::abandon_payment`]: crate::ln::channelmanager::ChannelManager::abandon_payment
 518         PaymentPathFailed {
 519                 /// The `payment_id` passed to [`ChannelManager::send_payment`].
 520                 ///
 521                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 522                 /// [`ChannelManager::abandon_payment`]: crate::ln::channelmanager::ChannelManager::abandon_payment
 523                 payment_id: Option<PaymentId>,
 524                 /// The hash that was given to [`ChannelManager::send_payment`].
 525                 ///
 526                 /// [`ChannelManager::send_payment`]: crate::ln::channelmanager::ChannelManager::send_payment
 527                 payment_hash: PaymentHash,
 528                 /// Indicates the payment was rejected for some reason by the recipient. This implies that
 529                 /// the payment has failed, not just the route in question. If this is not set, the payment may
 530                 /// be retried via a different route.
 531                 payment_failed_permanently: bool,
 532                 /// Extra error details based on the failure type. May contain an update that needs to be
 533                 /// applied to the [`NetworkGraph`].
 534                 ///
 535                 /// [`NetworkGraph`]: crate::routing::gossip::NetworkGraph
 536                 failure: PathFailure,
 537                 /// The payment path that failed.
 538                 path: Path,
 539                 /// The channel responsible for the failed payment path.
 540                 ///
 541                 /// Note that for route hints or for the first hop in a path this may be an SCID alias and
 542                 /// may not refer to a channel in the public network graph. These aliases may also collide
 543                 /// with channels in the public network graph.
 544                 ///
 545                 /// If this is `Some`, then the corresponding channel should be avoided when the payment is
 546                 /// retried. May be `None` for older [`Event`] serializations.
 547                 short_channel_id: Option<u64>,
 548 #[cfg(test)]
 549                 error_code: Option<u16>,
 550 #[cfg(test)]
 551                 error_data: Option<Vec<u8>>,
 552         },
 553         /// Indicates that a probe payment we sent returned successful, i.e., only failed at the destination.
 554         ProbeSuccessful {
 555                 /// The id returned by [`ChannelManager::send_probe`].
 556                 ///
 557                 /// [`ChannelManager::send_probe`]: crate::ln::channelmanager::ChannelManager::send_probe
 558                 payment_id: PaymentId,
 559                 /// The hash generated by [`ChannelManager::send_probe`].
 560                 ///
 561                 /// [`ChannelManager::send_probe`]: crate::ln::channelmanager::ChannelManager::send_probe
 562                 payment_hash: PaymentHash,
 563                 /// The payment path that was successful.
 564                 path: Path,
 565         },
 566         /// Indicates that a probe payment we sent failed at an intermediary node on the path.
 567         ProbeFailed {
 568                 /// The id returned by [`ChannelManager::send_probe`].
 569                 ///
 570                 /// [`ChannelManager::send_probe`]: crate::ln::channelmanager::ChannelManager::send_probe
 571                 payment_id: PaymentId,
 572                 /// The hash generated by [`ChannelManager::send_probe`].
 573                 ///
 574                 /// [`ChannelManager::send_probe`]: crate::ln::channelmanager::ChannelManager::send_probe
 575                 payment_hash: PaymentHash,
 576                 /// The payment path that failed.
 577                 path: Path,
 578                 /// The channel responsible for the failed probe.
 579                 ///
 580                 /// Note that for route hints or for the first hop in a path this may be an SCID alias and
 581                 /// may not refer to a channel in the public network graph. These aliases may also collide
 582                 /// with channels in the public network graph.
 583                 short_channel_id: Option<u64>,
 584         },
 585         /// Used to indicate that [`ChannelManager::process_pending_htlc_forwards`] should be called at
 586         /// a time in the future.
 587         ///
 588         /// [`ChannelManager::process_pending_htlc_forwards`]: crate::ln::channelmanager::ChannelManager::process_pending_htlc_forwards
 589         PendingHTLCsForwardable {
 590                 /// The minimum amount of time that should be waited prior to calling
 591                 /// process_pending_htlc_forwards. To increase the effort required to correlate payments,
 592                 /// you should wait a random amount of time in roughly the range (now + time_forwardable,
 593                 /// now + 5*time_forwardable).
 594                 time_forwardable: Duration,
 595         },
 596         /// Used to indicate that we've intercepted an HTLC forward. This event will only be generated if
 597         /// you've encoded an intercept scid in the receiver's invoice route hints using
 598         /// [`ChannelManager::get_intercept_scid`] and have set [`UserConfig::accept_intercept_htlcs`].
 599         ///
 600         /// [`ChannelManager::forward_intercepted_htlc`] or
 601         /// [`ChannelManager::fail_intercepted_htlc`] MUST be called in response to this event. See
 602         /// their docs for more information.
 603         ///
 604         /// [`ChannelManager::get_intercept_scid`]: crate::ln::channelmanager::ChannelManager::get_intercept_scid
 605         /// [`UserConfig::accept_intercept_htlcs`]: crate::util::config::UserConfig::accept_intercept_htlcs
 606         /// [`ChannelManager::forward_intercepted_htlc`]: crate::ln::channelmanager::ChannelManager::forward_intercepted_htlc
 607         /// [`ChannelManager::fail_intercepted_htlc`]: crate::ln::channelmanager::ChannelManager::fail_intercepted_htlc
 608         HTLCIntercepted {
 609                 /// An id to help LDK identify which HTLC is being forwarded or failed.
 610                 intercept_id: InterceptId,
 611                 /// The fake scid that was programmed as the next hop's scid, generated using
 612                 /// [`ChannelManager::get_intercept_scid`].
 613                 ///
 614                 /// [`ChannelManager::get_intercept_scid`]: crate::ln::channelmanager::ChannelManager::get_intercept_scid
 615                 requested_next_hop_scid: u64,
 616                 /// The payment hash used for this HTLC.
 617                 payment_hash: PaymentHash,
 618                 /// How many msats were received on the inbound edge of this HTLC.
 619                 inbound_amount_msat: u64,
 620                 /// How many msats the payer intended to route to the next node. Depending on the reason you are
 621                 /// intercepting this payment, you might take a fee by forwarding less than this amount.
 622                 ///
 623                 /// Note that LDK will NOT check that expected fees were factored into this value. You MUST
 624                 /// check that whatever fee you want has been included here or subtract it as required. Further,
 625                 /// LDK will not stop you from forwarding more than you received.
 626                 expected_outbound_amount_msat: u64,
 627         },
 628         /// Used to indicate that an output which you should know how to spend was confirmed on chain
 629         /// and is now spendable.
 630         /// Such an output will *not* ever be spent by rust-lightning, and are not at risk of your
 631         /// counterparty spending them due to some kind of timeout. Thus, you need to store them
 632         /// somewhere and spend them when you create on-chain transactions.
 633         SpendableOutputs {
 634                 /// The outputs which you should store as spendable by you.
 635                 outputs: Vec<SpendableOutputDescriptor>,
 636         },
 637         /// This event is generated when a payment has been successfully forwarded through us and a
 638         /// forwarding fee earned.
 639         PaymentForwarded {
 640                 /// The incoming channel between the previous node and us. This is only `None` for events
 641                 /// generated or serialized by versions prior to 0.0.107.
 642                 prev_channel_id: Option<[u8; 32]>,
 643                 /// The outgoing channel between the next node and us. This is only `None` for events
 644                 /// generated or serialized by versions prior to 0.0.107.
 645                 next_channel_id: Option<[u8; 32]>,
 646                 /// The fee, in milli-satoshis, which was earned as a result of the payment.
 647                 ///
 648                 /// Note that if we force-closed the channel over which we forwarded an HTLC while the HTLC
 649                 /// was pending, the amount the next hop claimed will have been rounded down to the nearest
 650                 /// whole satoshi. Thus, the fee calculated here may be higher than expected as we still
 651                 /// claimed the full value in millisatoshis from the source. In this case,
 652                 /// `claim_from_onchain_tx` will be set.
 653                 ///
 654                 /// If the channel which sent us the payment has been force-closed, we will claim the funds
 655                 /// via an on-chain transaction. In that case we do not yet know the on-chain transaction
 656                 /// fees which we will spend and will instead set this to `None`. It is possible duplicate
 657                 /// `PaymentForwarded` events are generated for the same payment iff `fee_earned_msat` is
 658                 /// `None`.
 659                 fee_earned_msat: Option<u64>,
 660                 /// If this is `true`, the forwarded HTLC was claimed by our counterparty via an on-chain
 661                 /// transaction.
 662                 claim_from_onchain_tx: bool,
 663                 /// The final amount forwarded, in milli-satoshis, after the fee is deducted.
 664                 ///
 665                 /// The caveat described above the `fee_earned_msat` field applies here as well.
 666                 outbound_amount_forwarded_msat: Option<u64>,
 667         },
 668         /// Used to indicate that a channel with the given `channel_id` is being opened and pending
 669         /// confirmation on-chain.
 670         ///
 671         /// This event is emitted when the funding transaction has been signed and is broadcast to the
 672         /// network. For 0conf channels it will be immediately followed by the corresponding
 673         /// [`Event::ChannelReady`] event.
 674         ChannelPending {
 675                 /// The `channel_id` of the channel that is pending confirmation.
 676                 channel_id: [u8; 32],
 677                 /// The `user_channel_id` value passed in to [`ChannelManager::create_channel`] for outbound
 678                 /// channels, or to [`ChannelManager::accept_inbound_channel`] for inbound channels if
 679                 /// [`UserConfig::manually_accept_inbound_channels`] config flag is set to true. Otherwise
 680                 /// `user_channel_id` will be randomized for an inbound channel.
 681                 ///
 682                 /// [`ChannelManager::create_channel`]: crate::ln::channelmanager::ChannelManager::create_channel
 683                 /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
 684                 /// [`UserConfig::manually_accept_inbound_channels`]: crate::util::config::UserConfig::manually_accept_inbound_channels
 685                 user_channel_id: u128,
 686                 /// The `temporary_channel_id` this channel used to be known by during channel establishment.
 687                 ///
 688                 /// Will be `None` for channels created prior to LDK version 0.0.115.
 689                 former_temporary_channel_id: Option<[u8; 32]>,
 690                 /// The `node_id` of the channel counterparty.
 691                 counterparty_node_id: PublicKey,
 692                 /// The outpoint of the channel's funding transaction.
 693                 funding_txo: OutPoint,
 694         },
 695         /// Used to indicate that a channel with the given `channel_id` is ready to
 696         /// be used. This event is emitted either when the funding transaction has been confirmed
 697         /// on-chain, or, in case of a 0conf channel, when both parties have confirmed the channel
 698         /// establishment.
 699         ChannelReady {
 700                 /// The `channel_id` of the channel that is ready.
 701                 channel_id: [u8; 32],
 702                 /// The `user_channel_id` value passed in to [`ChannelManager::create_channel`] for outbound
 703                 /// channels, or to [`ChannelManager::accept_inbound_channel`] for inbound channels if
 704                 /// [`UserConfig::manually_accept_inbound_channels`] config flag is set to true. Otherwise
 705                 /// `user_channel_id` will be randomized for an inbound channel.
 706                 ///
 707                 /// [`ChannelManager::create_channel`]: crate::ln::channelmanager::ChannelManager::create_channel
 708                 /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
 709                 /// [`UserConfig::manually_accept_inbound_channels`]: crate::util::config::UserConfig::manually_accept_inbound_channels
 710                 user_channel_id: u128,
 711                 /// The `node_id` of the channel counterparty.
 712                 counterparty_node_id: PublicKey,
 713                 /// The features that this channel will operate with.
 714                 channel_type: ChannelTypeFeatures,
 715         },
 716         /// Used to indicate that a previously opened channel with the given `channel_id` is in the
 717         /// process of closure.
 718         ChannelClosed  {
 719                 /// The `channel_id` of the channel which has been closed. Note that on-chain transactions
 720                 /// resolving the channel are likely still awaiting confirmation.
 721                 channel_id: [u8; 32],
 722                 /// The `user_channel_id` value passed in to [`ChannelManager::create_channel`] for outbound
 723                 /// channels, or to [`ChannelManager::accept_inbound_channel`] for inbound channels if
 724                 /// [`UserConfig::manually_accept_inbound_channels`] config flag is set to true. Otherwise
 725                 /// `user_channel_id` will be randomized for inbound channels.
 726                 /// This may be zero for inbound channels serialized prior to 0.0.113 and will always be
 727                 /// zero for objects serialized with LDK versions prior to 0.0.102.
 728                 ///
 729                 /// [`ChannelManager::create_channel`]: crate::ln::channelmanager::ChannelManager::create_channel
 730                 /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
 731                 /// [`UserConfig::manually_accept_inbound_channels`]: crate::util::config::UserConfig::manually_accept_inbound_channels
 732                 user_channel_id: u128,
 733                 /// The reason the channel was closed.
 734                 reason: ClosureReason
 735         },
 736         /// Used to indicate to the user that they can abandon the funding transaction and recycle the
 737         /// inputs for another purpose.
 738         DiscardFunding {
 739                 /// The channel_id of the channel which has been closed.
 740                 channel_id: [u8; 32],
 741                 /// The full transaction received from the user
 742                 transaction: Transaction
 743         },
 744         /// Indicates a request to open a new channel by a peer.
 745         ///
 746         /// To accept the request, call [`ChannelManager::accept_inbound_channel`]. To reject the
 747         /// request, call [`ChannelManager::force_close_without_broadcasting_txn`].
 748         ///
 749         /// The event is only triggered when a new open channel request is received and the
 750         /// [`UserConfig::manually_accept_inbound_channels`] config flag is set to true.
 751         ///
 752         /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
 753         /// [`ChannelManager::force_close_without_broadcasting_txn`]: crate::ln::channelmanager::ChannelManager::force_close_without_broadcasting_txn
 754         /// [`UserConfig::manually_accept_inbound_channels`]: crate::util::config::UserConfig::manually_accept_inbound_channels
 755         OpenChannelRequest {
 756                 /// The temporary channel ID of the channel requested to be opened.
 757                 ///
 758                 /// When responding to the request, the `temporary_channel_id` should be passed
 759                 /// back to the ChannelManager through [`ChannelManager::accept_inbound_channel`] to accept,
 760                 /// or through [`ChannelManager::force_close_without_broadcasting_txn`] to reject.
 761                 ///
 762                 /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
 763                 /// [`ChannelManager::force_close_without_broadcasting_txn`]: crate::ln::channelmanager::ChannelManager::force_close_without_broadcasting_txn
 764                 temporary_channel_id: [u8; 32],
 765                 /// The node_id of the counterparty requesting to open the channel.
 766                 ///
 767                 /// When responding to the request, the `counterparty_node_id` should be passed
 768                 /// back to the `ChannelManager` through [`ChannelManager::accept_inbound_channel`] to
 769                 /// accept the request, or through [`ChannelManager::force_close_without_broadcasting_txn`] to reject the
 770                 /// request.
 771                 ///
 772                 /// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
 773                 /// [`ChannelManager::force_close_without_broadcasting_txn`]: crate::ln::channelmanager::ChannelManager::force_close_without_broadcasting_txn
 774                 counterparty_node_id: PublicKey,
 775                 /// The channel value of the requested channel.
 776                 funding_satoshis: u64,
 777                 /// Our starting balance in the channel if the request is accepted, in milli-satoshi.
 778                 push_msat: u64,
 779                 /// The features that this channel will operate with. If you reject the channel, a
 780                 /// well-behaved counterparty may automatically re-attempt the channel with a new set of
 781                 /// feature flags.
 782                 ///
 783                 /// Note that if [`ChannelTypeFeatures::supports_scid_privacy`] returns true on this type,
 784                 /// the resulting [`ChannelManager`] will not be readable by versions of LDK prior to
 785                 /// 0.0.106.
 786                 ///
 787                 /// Furthermore, note that if [`ChannelTypeFeatures::supports_zero_conf`] returns true on this type,
 788                 /// the resulting [`ChannelManager`] will not be readable by versions of LDK prior to
 789                 /// 0.0.107. Channels setting this type also need to get manually accepted via
 790                 /// [`crate::ln::channelmanager::ChannelManager::accept_inbound_channel_from_trusted_peer_0conf`],
 791                 /// or will be rejected otherwise.
 792                 ///
 793                 /// [`ChannelManager`]: crate::ln::channelmanager::ChannelManager
 794                 channel_type: ChannelTypeFeatures,
 795         },
 796         /// Indicates that the HTLC was accepted, but could not be processed when or after attempting to
 797         /// forward it.
 798         ///
 799         /// Some scenarios where this event may be sent include:
 800         /// * Insufficient capacity in the outbound channel
 801         /// * While waiting to forward the HTLC, the channel it is meant to be forwarded through closes
 802         /// * When an unknown SCID is requested for forwarding a payment.
 803         /// * Expected MPP amount has already been reached
 804         /// * The HTLC has timed out
 805         ///
 806         /// This event, however, does not get generated if an HTLC fails to meet the forwarding
 807         /// requirements (i.e. insufficient fees paid, or a CLTV that is too soon).
 808         HTLCHandlingFailed {
 809                 /// The channel over which the HTLC was received.
 810                 prev_channel_id: [u8; 32],
 811                 /// Destination of the HTLC that failed to be processed.
 812                 failed_next_destination: HTLCDestination,
 813         },
 814         #[cfg(anchors)]
 815         /// Indicates that a transaction originating from LDK needs to have its fee bumped. This event
 816         /// requires confirmed external funds to be readily available to spend.
 817         ///
 818         /// LDK does not currently generate this event. It is limited to the scope of channels with
 819         /// anchor outputs, which will be introduced in a future release.
 820         BumpTransaction(BumpTransactionEvent),
 821 }
 822
 823 impl Writeable for Event {
 824         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 825                 match self {
 826                         &Event::FundingGenerationReady { .. } => {
 827                                 0u8.write(writer)?;
 828                                 // We never write out FundingGenerationReady events as, upon disconnection, peers
 829                                 // drop any channels which have not yet exchanged funding_signed.
 830                         },
 831                         &Event::PaymentClaimable { ref payment_hash, ref amount_msat, ref purpose,
 832                                 ref receiver_node_id, ref via_channel_id, ref via_user_channel_id,
 833                                 ref claim_deadline, ref onion_fields
 834                         } => {
 835                                 1u8.write(writer)?;
 836                                 let mut payment_secret = None;
 837                                 let payment_preimage;
 838                                 match &purpose {
 839                                         PaymentPurpose::InvoicePayment { payment_preimage: preimage, payment_secret: secret } => {
 840                                                 payment_secret = Some(secret);
 841                                                 payment_preimage = *preimage;
 842                                         },
 843                                         PaymentPurpose::SpontaneousPayment(preimage) => {
 844                                                 payment_preimage = Some(*preimage);
 845                                         }
 846                                 }
 847                                 write_tlv_fields!(writer, {
 848                                         (0, payment_hash, required),
 849                                         (1, receiver_node_id, option),
 850                                         (2, payment_secret, option),
 851                                         (3, via_channel_id, option),
 852                                         (4, amount_msat, required),
 853                                         (5, via_user_channel_id, option),
 854                                         (6, 0u64, required), // user_payment_id required for compatibility with 0.0.103 and earlier
 855                                         (7, claim_deadline, option),
 856                                         (8, payment_preimage, option),
 857                                         (9, onion_fields, option),
 858                                 });
 859                         },
 860                         &Event::PaymentSent { ref payment_id, ref payment_preimage, ref payment_hash, ref fee_paid_msat } => {
 861                                 2u8.write(writer)?;
 862                                 write_tlv_fields!(writer, {
 863                                         (0, payment_preimage, required),
 864                                         (1, payment_hash, required),
 865                                         (3, payment_id, option),
 866                                         (5, fee_paid_msat, option),
 867                                 });
 868                         },
 869                         &Event::PaymentPathFailed {
 870                                 ref payment_id, ref payment_hash, ref payment_failed_permanently, ref failure,
 871                                 ref path, ref short_channel_id,
 872                                 #[cfg(test)]
 873                                 ref error_code,
 874                                 #[cfg(test)]
 875                                 ref error_data,
 876                         } => {
 877                                 3u8.write(writer)?;
 878                                 #[cfg(test)]
 879                                 error_code.write(writer)?;
 880                                 #[cfg(test)]
 881                                 error_data.write(writer)?;
 882                                 write_tlv_fields!(writer, {
 883                                         (0, payment_hash, required),
 884                                         (1, None::<NetworkUpdate>, option), // network_update in LDK versions prior to 0.0.114
 885                                         (2, payment_failed_permanently, required),
 886                                         (3, false, required), // all_paths_failed in LDK versions prior to 0.0.114
 887                                         (4, path.blinded_tail, option),
 888                                         (5, path.hops, vec_type),
 889                                         (7, short_channel_id, option),
 890                                         (9, None::<RouteParameters>, option), // retry in LDK versions prior to 0.0.115
 891                                         (11, payment_id, option),
 892                                         (13, failure, required),
 893                                 });
 894                         },
 895                         &Event::PendingHTLCsForwardable { time_forwardable: _ } => {
 896                                 4u8.write(writer)?;
 897                                 // Note that we now ignore these on the read end as we'll re-generate them in
 898                                 // ChannelManager, we write them here only for backwards compatibility.
 899                         },
 900                         &Event::SpendableOutputs { ref outputs } => {
 901                                 5u8.write(writer)?;
 902                                 write_tlv_fields!(writer, {
 903                                         (0, WithoutLength(outputs), required),
 904                                 });
 905                         },
 906                         &Event::HTLCIntercepted { requested_next_hop_scid, payment_hash, inbound_amount_msat, expected_outbound_amount_msat, intercept_id } => {
 907                                 6u8.write(writer)?;
 908                                 let intercept_scid = InterceptNextHop::FakeScid { requested_next_hop_scid };
 909                                 write_tlv_fields!(writer, {
 910                                         (0, intercept_id, required),
 911                                         (2, intercept_scid, required),
 912                                         (4, payment_hash, required),
 913                                         (6, inbound_amount_msat, required),
 914                                         (8, expected_outbound_amount_msat, required),
 915                                 });
 916                         }
 917                         &Event::PaymentForwarded {
 918                                 fee_earned_msat, prev_channel_id, claim_from_onchain_tx,
 919                                 next_channel_id, outbound_amount_forwarded_msat
 920                         } => {
 921                                 7u8.write(writer)?;
 922                                 write_tlv_fields!(writer, {
 923                                         (0, fee_earned_msat, option),
 924                                         (1, prev_channel_id, option),
 925                                         (2, claim_from_onchain_tx, required),
 926                                         (3, next_channel_id, option),
 927                                         (5, outbound_amount_forwarded_msat, option),
 928                                 });
 929                         },
 930                         &Event::ChannelClosed { ref channel_id, ref user_channel_id, ref reason } => {
 931                                 9u8.write(writer)?;
 932                                 // `user_channel_id` used to be a single u64 value. In order to remain backwards
 933                                 // compatible with versions prior to 0.0.113, the u128 is serialized as two
 934                                 // separate u64 values.
 935                                 let user_channel_id_low = *user_channel_id as u64;
 936                                 let user_channel_id_high = (*user_channel_id >> 64) as u64;
 937                                 write_tlv_fields!(writer, {
 938                                         (0, channel_id, required),
 939                                         (1, user_channel_id_low, required),
 940                                         (2, reason, required),
 941                                         (3, user_channel_id_high, required),
 942                                 });
 943                         },
 944                         &Event::DiscardFunding { ref channel_id, ref transaction } => {
 945                                 11u8.write(writer)?;
 946                                 write_tlv_fields!(writer, {
 947                                         (0, channel_id, required),
 948                                         (2, transaction, required)
 949                                 })
 950                         },
 951                         &Event::PaymentPathSuccessful { ref payment_id, ref payment_hash, ref path } => {
 952                                 13u8.write(writer)?;
 953                                 write_tlv_fields!(writer, {
 954                                         (0, payment_id, required),
 955                                         (2, payment_hash, option),
 956                                         (4, path.hops, vec_type),
 957                                         (6, path.blinded_tail, option),
 958                                 })
 959                         },
 960                         &Event::PaymentFailed { ref payment_id, ref payment_hash, ref reason } => {
 961                                 15u8.write(writer)?;
 962                                 write_tlv_fields!(writer, {
 963                                         (0, payment_id, required),
 964                                         (1, reason, option),
 965                                         (2, payment_hash, required),
 966                                 })
 967                         },
 968                         &Event::OpenChannelRequest { .. } => {
 969                                 17u8.write(writer)?;
 970                                 // We never write the OpenChannelRequest events as, upon disconnection, peers
 971                                 // drop any channels which have not yet exchanged funding_signed.
 972                         },
 973                         &Event::PaymentClaimed { ref payment_hash, ref amount_msat, ref purpose, ref receiver_node_id } => {
 974                                 19u8.write(writer)?;
 975                                 write_tlv_fields!(writer, {
 976                                         (0, payment_hash, required),
 977                                         (1, receiver_node_id, option),
 978                                         (2, purpose, required),
 979                                         (4, amount_msat, required),
 980                                 });
 981                         },
 982                         &Event::ProbeSuccessful { ref payment_id, ref payment_hash, ref path } => {
 983                                 21u8.write(writer)?;
 984                                 write_tlv_fields!(writer, {
 985                                         (0, payment_id, required),
 986                                         (2, payment_hash, required),
 987                                         (4, path.hops, vec_type),
 988                                         (6, path.blinded_tail, option),
 989                                 })
 990                         },
 991                         &Event::ProbeFailed { ref payment_id, ref payment_hash, ref path, ref short_channel_id } => {
 992                                 23u8.write(writer)?;
 993                                 write_tlv_fields!(writer, {
 994                                         (0, payment_id, required),
 995                                         (2, payment_hash, required),
 996                                         (4, path.hops, vec_type),
 997                                         (6, short_channel_id, option),
 998                                         (8, path.blinded_tail, option),
 999                                 })
1000                         },
1001                         &Event::HTLCHandlingFailed { ref prev_channel_id, ref failed_next_destination } => {
1002                                 25u8.write(writer)?;
1003                                 write_tlv_fields!(writer, {
1004                                         (0, prev_channel_id, required),
1005                                         (2, failed_next_destination, required),
1006                                 })
1007                         },
1008                         #[cfg(anchors)]
1009                         &Event::BumpTransaction(ref event)=> {
1010                                 27u8.write(writer)?;
1011                                 match event {
1012                                         // We never write the ChannelClose|HTLCResolution events as they'll be replayed
1013                                         // upon restarting anyway if they remain unresolved.
1014                                         BumpTransactionEvent::ChannelClose { .. } => {}
1015                                         BumpTransactionEvent::HTLCResolution { .. } => {}
1016                                 }
1017                                 write_tlv_fields!(writer, {}); // Write a length field for forwards compat
1018                         }
1019                         &Event::ChannelReady { ref channel_id, ref user_channel_id, ref counterparty_node_id, ref channel_type } => {
1020                                 29u8.write(writer)?;
1021                                 write_tlv_fields!(writer, {
1022                                         (0, channel_id, required),
1023                                         (2, user_channel_id, required),
1024                                         (4, counterparty_node_id, required),
1025                                         (6, channel_type, required),
1026                                 });
1027                         },
1028                         &Event::ChannelPending { ref channel_id, ref user_channel_id, ref former_temporary_channel_id, ref counterparty_node_id, ref funding_txo } => {
1029                                 31u8.write(writer)?;
1030                                 write_tlv_fields!(writer, {
1031                                         (0, channel_id, required),
1032                                         (2, user_channel_id, required),
1033                                         (4, former_temporary_channel_id, required),
1034                                         (6, counterparty_node_id, required),
1035                                         (8, funding_txo, required),
1036                                 });
1037                         },
1038                         // Note that, going forward, all new events must only write data inside of
1039                         // `write_tlv_fields`. Versions 0.0.101+ will ignore odd-numbered events that write
1040                         // data via `write_tlv_fields`.
1041                 }
1042                 Ok(())
1043         }
1044 }
1045 impl MaybeReadable for Event {
1046         fn read<R: io::Read>(reader: &mut R) -> Result<Option<Self>, msgs::DecodeError> {
1047                 match Readable::read(reader)? {
1048                         // Note that we do not write a length-prefixed TLV for FundingGenerationReady events,
1049                         // unlike all other events, thus we return immediately here.
1050                         0u8 => Ok(None),
1051                         1u8 => {
1052                                 let f = || {
1053                                         let mut payment_hash = PaymentHash([0; 32]);
1054                                         let mut payment_preimage = None;
1055                                         let mut payment_secret = None;
1056                                         let mut amount_msat = 0;
1057                                         let mut receiver_node_id = None;
1058                                         let mut _user_payment_id = None::<u64>; // For compatibility with 0.0.103 and earlier
1059                                         let mut via_channel_id = None;
1060                                         let mut claim_deadline = None;
1061                                         let mut via_user_channel_id = None;
1062                                         let mut onion_fields = None;
1063                                         read_tlv_fields!(reader, {
1064                                                 (0, payment_hash, required),
1065                                                 (1, receiver_node_id, option),
1066                                                 (2, payment_secret, option),
1067                                                 (3, via_channel_id, option),
1068                                                 (4, amount_msat, required),
1069                                                 (5, via_user_channel_id, option),
1070                                                 (6, _user_payment_id, option),
1071                                                 (7, claim_deadline, option),
1072                                                 (8, payment_preimage, option),
1073                                                 (9, onion_fields, option),
1074                                         });
1075                                         let purpose = match payment_secret {
1076                                                 Some(secret) => PaymentPurpose::InvoicePayment {
1077                                                         payment_preimage,
1078                                                         payment_secret: secret
1079                                                 },
1080                                                 None if payment_preimage.is_some() => PaymentPurpose::SpontaneousPayment(payment_preimage.unwrap()),
1081                                                 None => return Err(msgs::DecodeError::InvalidValue),
1082                                         };
1083                                         Ok(Some(Event::PaymentClaimable {
1084                                                 receiver_node_id,
1085                                                 payment_hash,
1086                                                 amount_msat,
1087                                                 purpose,
1088                                                 via_channel_id,
1089                                                 via_user_channel_id,
1090                                                 claim_deadline,
1091                                                 onion_fields,
1092                                         }))
1093                                 };
1094                                 f()
1095                         },
1096                         2u8 => {
1097                                 let f = || {
1098                                         let mut payment_preimage = PaymentPreimage([0; 32]);
1099                                         let mut payment_hash = None;
1100                                         let mut payment_id = None;
1101                                         let mut fee_paid_msat = None;
1102                                         read_tlv_fields!(reader, {
1103                                                 (0, payment_preimage, required),
1104                                                 (1, payment_hash, option),
1105                                                 (3, payment_id, option),
1106                                                 (5, fee_paid_msat, option),
1107                                         });
1108                                         if payment_hash.is_none() {
1109                                                 payment_hash = Some(PaymentHash(Sha256::hash(&payment_preimage.0[..]).into_inner()));
1110                                         }
1111                                         Ok(Some(Event::PaymentSent {
1112                                                 payment_id,
1113                                                 payment_preimage,
1114                                                 payment_hash: payment_hash.unwrap(),
1115                                                 fee_paid_msat,
1116                                         }))
1117                                 };
1118                                 f()
1119                         },
1120                         3u8 => {
1121                                 let f = || {
1122                                         #[cfg(test)]
1123                                         let error_code = Readable::read(reader)?;
1124                                         #[cfg(test)]
1125                                         let error_data = Readable::read(reader)?;
1126                                         let mut payment_hash = PaymentHash([0; 32]);
1127                                         let mut payment_failed_permanently = false;
1128                                         let mut network_update = None;
1129                                         let mut blinded_tail: Option<BlindedTail> = None;
1130                                         let mut path: Option<Vec<RouteHop>> = Some(vec![]);
1131                                         let mut short_channel_id = None;
1132                                         let mut payment_id = None;
1133                                         let mut failure_opt = None;
1134                                         read_tlv_fields!(reader, {
1135                                                 (0, payment_hash, required),
1136                                                 (1, network_update, upgradable_option),
1137                                                 (2, payment_failed_permanently, required),
1138                                                 (4, blinded_tail, option),
1139                                                 (5, path, vec_type),
1140                                                 (7, short_channel_id, option),
1141                                                 (11, payment_id, option),
1142                                                 (13, failure_opt, upgradable_option),
1143                                         });
1144                                         let failure = failure_opt.unwrap_or_else(|| PathFailure::OnPath { network_update });
1145                                         Ok(Some(Event::PaymentPathFailed {
1146                                                 payment_id,
1147                                                 payment_hash,
1148                                                 payment_failed_permanently,
1149                                                 failure,
1150                                                 path: Path { hops: path.unwrap(), blinded_tail },
1151                                                 short_channel_id,
1152                                                 #[cfg(test)]
1153                                                 error_code,
1154                                                 #[cfg(test)]
1155                                                 error_data,
1156                                         }))
1157                                 };
1158                                 f()
1159                         },
1160                         4u8 => Ok(None),
1161                         5u8 => {
1162                                 let f = || {
1163                                         let mut outputs = WithoutLength(Vec::new());
1164                                         read_tlv_fields!(reader, {
1165                                                 (0, outputs, required),
1166                                         });
1167                                         Ok(Some(Event::SpendableOutputs { outputs: outputs.0 }))
1168                                 };
1169                                 f()
1170                         },
1171                         6u8 => {
1172                                 let mut payment_hash = PaymentHash([0; 32]);
1173                                 let mut intercept_id = InterceptId([0; 32]);
1174                                 let mut requested_next_hop_scid = InterceptNextHop::FakeScid { requested_next_hop_scid: 0 };
1175                                 let mut inbound_amount_msat = 0;
1176                                 let mut expected_outbound_amount_msat = 0;
1177                                 read_tlv_fields!(reader, {
1178                                         (0, intercept_id, required),
1179                                         (2, requested_next_hop_scid, required),
1180                                         (4, payment_hash, required),
1181                                         (6, inbound_amount_msat, required),
1182                                         (8, expected_outbound_amount_msat, required),
1183                                 });
1184                                 let next_scid = match requested_next_hop_scid {
1185                                         InterceptNextHop::FakeScid { requested_next_hop_scid: scid } => scid
1186                                 };
1187                                 Ok(Some(Event::HTLCIntercepted {
1188                                         payment_hash,
1189                                         requested_next_hop_scid: next_scid,
1190                                         inbound_amount_msat,
1191                                         expected_outbound_amount_msat,
1192                                         intercept_id,
1193                                 }))
1194                         },
1195                         7u8 => {
1196                                 let f = || {
1197                                         let mut fee_earned_msat = None;
1198                                         let mut prev_channel_id = None;
1199                                         let mut claim_from_onchain_tx = false;
1200                                         let mut next_channel_id = None;
1201                                         let mut outbound_amount_forwarded_msat = None;
1202                                         read_tlv_fields!(reader, {
1203                                                 (0, fee_earned_msat, option),
1204                                                 (1, prev_channel_id, option),
1205                                                 (2, claim_from_onchain_tx, required),
1206                                                 (3, next_channel_id, option),
1207                                                 (5, outbound_amount_forwarded_msat, option),
1208                                         });
1209                                         Ok(Some(Event::PaymentForwarded {
1210                                                 fee_earned_msat, prev_channel_id, claim_from_onchain_tx, next_channel_id,
1211                                                 outbound_amount_forwarded_msat
1212                                         }))
1213                                 };
1214                                 f()
1215                         },
1216                         9u8 => {
1217                                 let f = || {
1218                                         let mut channel_id = [0; 32];
1219                                         let mut reason = UpgradableRequired(None);
1220                                         let mut user_channel_id_low_opt: Option<u64> = None;
1221                                         let mut user_channel_id_high_opt: Option<u64> = None;
1222                                         read_tlv_fields!(reader, {
1223                                                 (0, channel_id, required),
1224                                                 (1, user_channel_id_low_opt, option),
1225                                                 (2, reason, upgradable_required),
1226                                                 (3, user_channel_id_high_opt, option),
1227                                         });
1228
1229                                         // `user_channel_id` used to be a single u64 value. In order to remain
1230                                         // backwards compatible with versions prior to 0.0.113, the u128 is serialized
1231                                         // as two separate u64 values.
1232                                         let user_channel_id = (user_channel_id_low_opt.unwrap_or(0) as u128) +
1233                                                 ((user_channel_id_high_opt.unwrap_or(0) as u128) << 64);
1234
1235                                         Ok(Some(Event::ChannelClosed { channel_id, user_channel_id, reason: _init_tlv_based_struct_field!(reason, upgradable_required) }))
1236                                 };
1237                                 f()
1238                         },
1239                         11u8 => {
1240                                 let f = || {
1241                                         let mut channel_id = [0; 32];
1242                                         let mut transaction = Transaction{ version: 2, lock_time: PackedLockTime::ZERO, input: Vec::new(), output: Vec::new() };
1243                                         read_tlv_fields!(reader, {
1244                                                 (0, channel_id, required),
1245                                                 (2, transaction, required),
1246                                         });
1247                                         Ok(Some(Event::DiscardFunding { channel_id, transaction } ))
1248                                 };
1249                                 f()
1250                         },
1251                         13u8 => {
1252                                 let f = || {
1253                                         _init_and_read_tlv_fields!(reader, {
1254                                                 (0, payment_id, required),
1255                                                 (2, payment_hash, option),
1256                                                 (4, path, vec_type),
1257                                                 (6, blinded_tail, option),
1258                                         });
1259                                         Ok(Some(Event::PaymentPathSuccessful {
1260                                                 payment_id: payment_id.0.unwrap(),
1261                                                 payment_hash,
1262                                                 path: Path { hops: path.unwrap(), blinded_tail },
1263                                         }))
1264                                 };
1265                                 f()
1266                         },
1267                         15u8 => {
1268                                 let f = || {
1269                                         let mut payment_hash = PaymentHash([0; 32]);
1270                                         let mut payment_id = PaymentId([0; 32]);
1271                                         let mut reason = None;
1272                                         read_tlv_fields!(reader, {
1273                                                 (0, payment_id, required),
1274                                                 (1, reason, upgradable_option),
1275                                                 (2, payment_hash, required),
1276                                         });
1277                                         Ok(Some(Event::PaymentFailed {
1278                                                 payment_id,
1279                                                 payment_hash,
1280                                                 reason,
1281                                         }))
1282                                 };
1283                                 f()
1284                         },
1285                         17u8 => {
1286                                 // Value 17 is used for `Event::OpenChannelRequest`.
1287                                 Ok(None)
1288                         },
1289                         19u8 => {
1290                                 let f = || {
1291                                         let mut payment_hash = PaymentHash([0; 32]);
1292                                         let mut purpose = UpgradableRequired(None);
1293                                         let mut amount_msat = 0;
1294                                         let mut receiver_node_id = None;
1295                                         read_tlv_fields!(reader, {
1296                                                 (0, payment_hash, required),
1297                                                 (1, receiver_node_id, option),
1298                                                 (2, purpose, upgradable_required),
1299                                                 (4, amount_msat, required),
1300                                         });
1301                                         Ok(Some(Event::PaymentClaimed {
1302                                                 receiver_node_id,
1303                                                 payment_hash,
1304                                                 purpose: _init_tlv_based_struct_field!(purpose, upgradable_required),
1305                                                 amount_msat,
1306                                         }))
1307                                 };
1308                                 f()
1309                         },
1310                         21u8 => {
1311                                 let f = || {
1312                                         _init_and_read_tlv_fields!(reader, {
1313                                                 (0, payment_id, required),
1314                                                 (2, payment_hash, required),
1315                                                 (4, path, vec_type),
1316                                                 (6, blinded_tail, option),
1317                                         });
1318                                         Ok(Some(Event::ProbeSuccessful {
1319                                                 payment_id: payment_id.0.unwrap(),
1320                                                 payment_hash: payment_hash.0.unwrap(),
1321                                                 path: Path { hops: path.unwrap(), blinded_tail },
1322                                         }))
1323                                 };
1324                                 f()
1325                         },
1326                         23u8 => {
1327                                 let f = || {
1328                                         _init_and_read_tlv_fields!(reader, {
1329                                                 (0, payment_id, required),
1330                                                 (2, payment_hash, required),
1331                                                 (4, path, vec_type),
1332                                                 (6, short_channel_id, option),
1333                                                 (8, blinded_tail, option),
1334                                         });
1335                                         Ok(Some(Event::ProbeFailed {
1336                                                 payment_id: payment_id.0.unwrap(),
1337                                                 payment_hash: payment_hash.0.unwrap(),
1338                                                 path: Path { hops: path.unwrap(), blinded_tail },
1339                                                 short_channel_id,
1340                                         }))
1341                                 };
1342                                 f()
1343                         },
1344                         25u8 => {
1345                                 let f = || {
1346                                         let mut prev_channel_id = [0; 32];
1347                                         let mut failed_next_destination_opt = UpgradableRequired(None);
1348                                         read_tlv_fields!(reader, {
1349                                                 (0, prev_channel_id, required),
1350                                                 (2, failed_next_destination_opt, upgradable_required),
1351                                         });
1352                                         Ok(Some(Event::HTLCHandlingFailed {
1353                                                 prev_channel_id,
1354                                                 failed_next_destination: _init_tlv_based_struct_field!(failed_next_destination_opt, upgradable_required),
1355                                         }))
1356                                 };
1357                                 f()
1358                         },
1359                         27u8 => Ok(None),
1360                         29u8 => {
1361                                 let f = || {
1362                                         let mut channel_id = [0; 32];
1363                                         let mut user_channel_id: u128 = 0;
1364                                         let mut counterparty_node_id = RequiredWrapper(None);
1365                                         let mut channel_type = RequiredWrapper(None);
1366                                         read_tlv_fields!(reader, {
1367                                                 (0, channel_id, required),
1368                                                 (2, user_channel_id, required),
1369                                                 (4, counterparty_node_id, required),
1370                                                 (6, channel_type, required),
1371                                         });
1372
1373                                         Ok(Some(Event::ChannelReady {
1374                                                 channel_id,
1375                                                 user_channel_id,
1376                                                 counterparty_node_id: counterparty_node_id.0.unwrap(),
1377                                                 channel_type: channel_type.0.unwrap()
1378                                         }))
1379                                 };
1380                                 f()
1381                         },
1382                         31u8 => {
1383                                 let f = || {
1384                                         let mut channel_id = [0; 32];
1385                                         let mut user_channel_id: u128 = 0;
1386                                         let mut former_temporary_channel_id = None;
1387                                         let mut counterparty_node_id = RequiredWrapper(None);
1388                                         let mut funding_txo = RequiredWrapper(None);
1389                                         read_tlv_fields!(reader, {
1390                                                 (0, channel_id, required),
1391                                                 (2, user_channel_id, required),
1392                                                 (4, former_temporary_channel_id, required),
1393                                                 (6, counterparty_node_id, required),
1394                                                 (8, funding_txo, required),
1395                                         });
1396
1397                                         Ok(Some(Event::ChannelPending {
1398                                                 channel_id,
1399                                                 user_channel_id,
1400                                                 former_temporary_channel_id,
1401                                                 counterparty_node_id: counterparty_node_id.0.unwrap(),
1402                                                 funding_txo: funding_txo.0.unwrap()
1403                                         }))
1404                                 };
1405                                 f()
1406                         },
1407                         // Versions prior to 0.0.100 did not ignore odd types, instead returning InvalidValue.
1408                         // Version 0.0.100 failed to properly ignore odd types, possibly resulting in corrupt
1409                         // reads.
1410                         x if x % 2 == 1 => {
1411                                 // If the event is of unknown type, assume it was written with `write_tlv_fields`,
1412                                 // which prefixes the whole thing with a length BigSize. Because the event is
1413                                 // odd-type unknown, we should treat it as `Ok(None)` even if it has some TLV
1414                                 // fields that are even. Thus, we avoid using `read_tlv_fields` and simply read
1415                                 // exactly the number of bytes specified, ignoring them entirely.
1416                                 let tlv_len: BigSize = Readable::read(reader)?;
1417                                 FixedLengthReader::new(reader, tlv_len.0)
1418                                         .eat_remaining().map_err(|_| msgs::DecodeError::ShortRead)?;
1419                                 Ok(None)
1420                         },
1421                         _ => Err(msgs::DecodeError::InvalidValue)
1422                 }
1423         }
1424 }
1425
1426 /// An event generated by ChannelManager which indicates a message should be sent to a peer (or
1427 /// broadcast to most peers).
1428 /// These events are handled by PeerManager::process_events if you are using a PeerManager.
1429 #[derive(Clone, Debug)]
1430 pub enum MessageSendEvent {
1431         /// Used to indicate that we've accepted a channel open and should send the accept_channel
1432         /// message provided to the given peer.
1433         SendAcceptChannel {
1434                 /// The node_id of the node which should receive this message
1435                 node_id: PublicKey,
1436                 /// The message which should be sent.
1437                 msg: msgs::AcceptChannel,
1438         },
1439         /// Used to indicate that we've initiated a channel open and should send the open_channel
1440         /// message provided to the given peer.
1441         SendOpenChannel {
1442                 /// The node_id of the node which should receive this message
1443                 node_id: PublicKey,
1444                 /// The message which should be sent.
1445                 msg: msgs::OpenChannel,
1446         },
1447         /// Used to indicate that a funding_created message should be sent to the peer with the given node_id.
1448         SendFundingCreated {
1449                 /// The node_id of the node which should receive this message
1450                 node_id: PublicKey,
1451                 /// The message which should be sent.
1452                 msg: msgs::FundingCreated,
1453         },
1454         /// Used to indicate that a funding_signed message should be sent to the peer with the given node_id.
1455         SendFundingSigned {
1456                 /// The node_id of the node which should receive this message
1457                 node_id: PublicKey,
1458                 /// The message which should be sent.
1459                 msg: msgs::FundingSigned,
1460         },
1461         /// Used to indicate that a channel_ready message should be sent to the peer with the given node_id.
1462         SendChannelReady {
1463                 /// The node_id of the node which should receive these message(s)
1464                 node_id: PublicKey,
1465                 /// The channel_ready message which should be sent.
1466                 msg: msgs::ChannelReady,
1467         },
1468         /// Used to indicate that an announcement_signatures message should be sent to the peer with the given node_id.
1469         SendAnnouncementSignatures {
1470                 /// The node_id of the node which should receive these message(s)
1471                 node_id: PublicKey,
1472                 /// The announcement_signatures message which should be sent.
1473                 msg: msgs::AnnouncementSignatures,
1474         },
1475         /// Used to indicate that a series of HTLC update messages, as well as a commitment_signed
1476         /// message should be sent to the peer with the given node_id.
1477         UpdateHTLCs {
1478                 /// The node_id of the node which should receive these message(s)
1479                 node_id: PublicKey,
1480                 /// The update messages which should be sent. ALL messages in the struct should be sent!
1481                 updates: msgs::CommitmentUpdate,
1482         },
1483         /// Used to indicate that a revoke_and_ack message should be sent to the peer with the given node_id.
1484         SendRevokeAndACK {
1485                 /// The node_id of the node which should receive this message
1486                 node_id: PublicKey,
1487                 /// The message which should be sent.
1488                 msg: msgs::RevokeAndACK,
1489         },
1490         /// Used to indicate that a closing_signed message should be sent to the peer with the given node_id.
1491         SendClosingSigned {
1492                 /// The node_id of the node which should receive this message
1493                 node_id: PublicKey,
1494                 /// The message which should be sent.
1495                 msg: msgs::ClosingSigned,
1496         },
1497         /// Used to indicate that a shutdown message should be sent to the peer with the given node_id.
1498         SendShutdown {
1499                 /// The node_id of the node which should receive this message
1500                 node_id: PublicKey,
1501                 /// The message which should be sent.
1502                 msg: msgs::Shutdown,
1503         },
1504         /// Used to indicate that a channel_reestablish message should be sent to the peer with the given node_id.
1505         SendChannelReestablish {
1506                 /// The node_id of the node which should receive this message
1507                 node_id: PublicKey,
1508                 /// The message which should be sent.
1509                 msg: msgs::ChannelReestablish,
1510         },
1511         /// Used to send a channel_announcement and channel_update to a specific peer, likely on
1512         /// initial connection to ensure our peers know about our channels.
1513         SendChannelAnnouncement {
1514                 /// The node_id of the node which should receive this message
1515                 node_id: PublicKey,
1516                 /// The channel_announcement which should be sent.
1517                 msg: msgs::ChannelAnnouncement,
1518                 /// The followup channel_update which should be sent.
1519                 update_msg: msgs::ChannelUpdate,
1520         },
1521         /// Used to indicate that a channel_announcement and channel_update should be broadcast to all
1522         /// peers (except the peer with node_id either msg.contents.node_id_1 or msg.contents.node_id_2).
1523         ///
1524         /// Note that after doing so, you very likely (unless you did so very recently) want to
1525         /// broadcast a node_announcement (e.g. via [`PeerManager::broadcast_node_announcement`]). This
1526         /// ensures that any nodes which see our channel_announcement also have a relevant
1527         /// node_announcement, including relevant feature flags which may be important for routing
1528         /// through or to us.
1529         ///
1530         /// [`PeerManager::broadcast_node_announcement`]: crate::ln::peer_handler::PeerManager::broadcast_node_announcement
1531         BroadcastChannelAnnouncement {
1532                 /// The channel_announcement which should be sent.
1533                 msg: msgs::ChannelAnnouncement,
1534                 /// The followup channel_update which should be sent.
1535                 update_msg: Option<msgs::ChannelUpdate>,
1536         },
1537         /// Used to indicate that a channel_update should be broadcast to all peers.
1538         BroadcastChannelUpdate {
1539                 /// The channel_update which should be sent.
1540                 msg: msgs::ChannelUpdate,
1541         },
1542         /// Used to indicate that a node_announcement should be broadcast to all peers.
1543         BroadcastNodeAnnouncement {
1544                 /// The node_announcement which should be sent.
1545                 msg: msgs::NodeAnnouncement,
1546         },
1547         /// Used to indicate that a channel_update should be sent to a single peer.
1548         /// In contrast to [`Self::BroadcastChannelUpdate`], this is used when the channel is a
1549         /// private channel and we shouldn't be informing all of our peers of channel parameters.
1550         SendChannelUpdate {
1551                 /// The node_id of the node which should receive this message
1552                 node_id: PublicKey,
1553                 /// The channel_update which should be sent.
1554                 msg: msgs::ChannelUpdate,
1555         },
1556         /// Broadcast an error downstream to be handled
1557         HandleError {
1558                 /// The node_id of the node which should receive this message
1559                 node_id: PublicKey,
1560                 /// The action which should be taken.
1561                 action: msgs::ErrorAction
1562         },
1563         /// Query a peer for channels with funding transaction UTXOs in a block range.
1564         SendChannelRangeQuery {
1565                 /// The node_id of this message recipient
1566                 node_id: PublicKey,
1567                 /// The query_channel_range which should be sent.
1568                 msg: msgs::QueryChannelRange,
1569         },
1570         /// Request routing gossip messages from a peer for a list of channels identified by
1571         /// their short_channel_ids.
1572         SendShortIdsQuery {
1573                 /// The node_id of this message recipient
1574                 node_id: PublicKey,
1575                 /// The query_short_channel_ids which should be sent.
1576                 msg: msgs::QueryShortChannelIds,
1577         },
1578         /// Sends a reply to a channel range query. This may be one of several SendReplyChannelRange events
1579         /// emitted during processing of the query.
1580         SendReplyChannelRange {
1581                 /// The node_id of this message recipient
1582                 node_id: PublicKey,
1583                 /// The reply_channel_range which should be sent.
1584                 msg: msgs::ReplyChannelRange,
1585         },
1586         /// Sends a timestamp filter for inbound gossip. This should be sent on each new connection to
1587         /// enable receiving gossip messages from the peer.
1588         SendGossipTimestampFilter {
1589                 /// The node_id of this message recipient
1590                 node_id: PublicKey,
1591                 /// The gossip_timestamp_filter which should be sent.
1592                 msg: msgs::GossipTimestampFilter,
1593         },
1594 }
1595
1596 /// A trait indicating an object may generate message send events
1597 pub trait MessageSendEventsProvider {
1598         /// Gets the list of pending events which were generated by previous actions, clearing the list
1599         /// in the process.
1600         fn get_and_clear_pending_msg_events(&self) -> Vec<MessageSendEvent>;
1601 }
1602
1603 /// A trait indicating an object may generate onion messages to send
1604 pub trait OnionMessageProvider {
1605         /// Gets the next pending onion message for the peer with the given node id.
1606         fn next_onion_message_for_peer(&self, peer_node_id: PublicKey) -> Option<msgs::OnionMessage>;
1607 }
1608
1609 /// A trait indicating an object may generate events.
1610 ///
1611 /// Events are processed by passing an [`EventHandler`] to [`process_pending_events`].
1612 ///
1613 /// Implementations of this trait may also feature an async version of event handling, as shown with
1614 /// [`ChannelManager::process_pending_events_async`] and
1615 /// [`ChainMonitor::process_pending_events_async`].
1616 ///
1617 /// # Requirements
1618 ///
1619 /// When using this trait, [`process_pending_events`] will call [`handle_event`] for each pending
1620 /// event since the last invocation.
1621 ///
1622 /// In order to ensure no [`Event`]s are lost, implementors of this trait will persist [`Event`]s
1623 /// and replay any unhandled events on startup. An [`Event`] is considered handled when
1624 /// [`process_pending_events`] returns, thus handlers MUST fully handle [`Event`]s and persist any
1625 /// relevant changes to disk *before* returning.
1626 ///
1627 /// Further, because an application may crash between an [`Event`] being handled and the
1628 /// implementor of this trait being re-serialized, [`Event`] handling must be idempotent - in
1629 /// effect, [`Event`]s may be replayed.
1630 ///
1631 /// Note, handlers may call back into the provider and thus deadlocking must be avoided. Be sure to
1632 /// consult the provider's documentation on the implication of processing events and how a handler
1633 /// may safely use the provider (e.g., see [`ChannelManager::process_pending_events`] and
1634 /// [`ChainMonitor::process_pending_events`]).
1635 ///
1636 /// (C-not implementable) As there is likely no reason for a user to implement this trait on their
1637 /// own type(s).
1638 ///
1639 /// [`process_pending_events`]: Self::process_pending_events
1640 /// [`handle_event`]: EventHandler::handle_event
1641 /// [`ChannelManager::process_pending_events`]: crate::ln::channelmanager::ChannelManager#method.process_pending_events
1642 /// [`ChainMonitor::process_pending_events`]: crate::chain::chainmonitor::ChainMonitor#method.process_pending_events
1643 /// [`ChannelManager::process_pending_events_async`]: crate::ln::channelmanager::ChannelManager::process_pending_events_async
1644 /// [`ChainMonitor::process_pending_events_async`]: crate::chain::chainmonitor::ChainMonitor::process_pending_events_async
1645 pub trait EventsProvider {
1646         /// Processes any events generated since the last call using the given event handler.
1647         ///
1648         /// See the trait-level documentation for requirements.
1649         fn process_pending_events<H: Deref>(&self, handler: H) where H::Target: EventHandler;
1650 }
1651
1652 /// A trait implemented for objects handling events from [`EventsProvider`].
1653 ///
1654 /// An async variation also exists for implementations of [`EventsProvider`] that support async
1655 /// event handling. The async event handler should satisfy the generic bounds: `F:
1656 /// core::future::Future, H: Fn(Event) -> F`.
1657 pub trait EventHandler {
1658         /// Handles the given [`Event`].
1659         ///
1660         /// See [`EventsProvider`] for details that must be considered when implementing this method.
1661         fn handle_event(&self, event: Event);
1662 }
1663
1664 impl<F> EventHandler for F where F: Fn(Event) {
1665         fn handle_event(&self, event: Event) {
1666                 self(event)
1667         }
1668 }
1669
1670 impl<T: EventHandler> EventHandler for Arc<T> {
1671         fn handle_event(&self, event: Event) {
1672                 self.deref().handle_event(event)
1673         }
1674 }