_ Git - rust-lightning/blob - lightning/src/events/mod.rs

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