_ Git - rust-lightning/blob - lightning/src/chain/onchaintx.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 //! The logic to build claims and bump in-flight transactions until confirmations.
  11 //!
  12 //! OnchainTxHandler objects are fully-part of ChannelMonitor and encapsulates all
  13 //! building, tracking, bumping and notifications functions.
  14
  15 use bitcoin::blockdata::locktime::absolute::LockTime;
  16 use bitcoin::blockdata::transaction::Transaction;
  17 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
  18 use bitcoin::blockdata::script::{Script, ScriptBuf};
  19 use bitcoin::hashes::{Hash, HashEngine};
  20 use bitcoin::hashes::sha256::Hash as Sha256;
  21 use bitcoin::hash_types::{Txid, BlockHash};
  22 use bitcoin::secp256k1::{Secp256k1, ecdsa::Signature};
  23 use bitcoin::secp256k1;
  24
  25 use crate::chain::chaininterface::compute_feerate_sat_per_1000_weight;
  26 use crate::sign::{ChannelDerivationParameters, HTLCDescriptor, ChannelSigner, EntropySource, SignerProvider, ecdsa::WriteableEcdsaChannelSigner};
  27 use crate::ln::msgs::DecodeError;
  28 use crate::ln::PaymentPreimage;
  29 use crate::ln::chan_utils::{self, ChannelTransactionParameters, HTLCOutputInCommitment, HolderCommitmentTransaction};
  30 use crate::chain::ClaimId;
  31 use crate::chain::chaininterface::{ConfirmationTarget, FeeEstimator, BroadcasterInterface, LowerBoundedFeeEstimator};
  32 use crate::chain::channelmonitor::{ANTI_REORG_DELAY, CLTV_SHARED_CLAIM_BUFFER};
  33 use crate::chain::package::{PackageSolvingData, PackageTemplate};
  34 use crate::util::logger::Logger;
  35 use crate::util::ser::{Readable, ReadableArgs, MaybeReadable, UpgradableRequired, Writer, Writeable, VecWriter};
  36
  37 use crate::io;
  38 use crate::prelude::*;
  39 use alloc::collections::BTreeMap;
  40 use core::cmp;
  41 use core::ops::Deref;
  42 use core::mem::replace;
  43 use core::mem::swap;
  44 use crate::ln::features::ChannelTypeFeatures;
  45
  46 const MAX_ALLOC_SIZE: usize = 64*1024;
  47
  48 /// An entry for an [`OnchainEvent`], stating the block height when the event was observed and the
  49 /// transaction causing it.
  50 ///
  51 /// Used to determine when the on-chain event can be considered safe from a chain reorganization.
  52 #[derive(Clone, PartialEq, Eq)]
  53 struct OnchainEventEntry {
  54         txid: Txid,
  55         height: u32,
  56         block_hash: Option<BlockHash>, // Added as optional, will be filled in for any entry generated on 0.0.113 or after
  57         event: OnchainEvent,
  58 }
  59
  60 impl OnchainEventEntry {
  61         fn confirmation_threshold(&self) -> u32 {
  62                 self.height + ANTI_REORG_DELAY - 1
  63         }
  64
  65         fn has_reached_confirmation_threshold(&self, height: u32) -> bool {
  66                 height >= self.confirmation_threshold()
  67         }
  68 }
  69
  70 /// Events for claims the [`OnchainTxHandler`] has generated. Once the events are considered safe
  71 /// from a chain reorg, the [`OnchainTxHandler`] will act accordingly.
  72 #[derive(Clone, PartialEq, Eq)]
  73 enum OnchainEvent {
  74         /// A pending request has been claimed by a transaction spending the exact same set of outpoints
  75         /// as the request. This claim can either be ours or from the counterparty. Once the claiming
  76         /// transaction has met [`ANTI_REORG_DELAY`] confirmations, we consider it final and remove the
  77         /// pending request.
  78         Claim {
  79                 claim_id: ClaimId,
  80         },
  81         /// The counterparty has claimed an outpoint from one of our pending requests through a
  82         /// different transaction than ours. If our transaction was attempting to claim multiple
  83         /// outputs, we need to drop the outpoint claimed by the counterparty and regenerate a new claim
  84         /// transaction for ourselves. We keep tracking, separately, the outpoint claimed by the
  85         /// counterparty up to [`ANTI_REORG_DELAY`] confirmations to ensure we attempt to re-claim it
  86         /// if the counterparty's claim is reorged from the chain.
  87         ContentiousOutpoint {
  88                 package: PackageTemplate,
  89         }
  90 }
  91
  92 impl Writeable for OnchainEventEntry {
  93         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
  94                 write_tlv_fields!(writer, {
  95                         (0, self.txid, required),
  96                         (1, self.block_hash, option),
  97                         (2, self.height, required),
  98                         (4, self.event, required),
  99                 });
 100                 Ok(())
 101         }
 102 }
 103
 104 impl MaybeReadable for OnchainEventEntry {
 105         fn read<R: io::Read>(reader: &mut R) -> Result<Option<Self>, DecodeError> {
 106                 let mut txid = Txid::all_zeros();
 107                 let mut height = 0;
 108                 let mut block_hash = None;
 109                 let mut event = UpgradableRequired(None);
 110                 read_tlv_fields!(reader, {
 111                         (0, txid, required),
 112                         (1, block_hash, option),
 113                         (2, height, required),
 114                         (4, event, upgradable_required),
 115                 });
 116                 Ok(Some(Self { txid, height, block_hash, event: _init_tlv_based_struct_field!(event, upgradable_required) }))
 117         }
 118 }
 119
 120 impl_writeable_tlv_based_enum_upgradable!(OnchainEvent,
 121         (0, Claim) => {
 122                 (0, claim_id, required),
 123         },
 124         (1, ContentiousOutpoint) => {
 125                 (0, package, required),
 126         },
 127 );
 128
 129 impl Readable for Option<Vec<Option<(usize, Signature)>>> {
 130         fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
 131                 match Readable::read(reader)? {
 132                         0u8 => Ok(None),
 133                         1u8 => {
 134                                 let vlen: u64 = Readable::read(reader)?;
 135                                 let mut ret = Vec::with_capacity(cmp::min(vlen as usize, MAX_ALLOC_SIZE / ::core::mem::size_of::<Option<(usize, Signature)>>()));
 136                                 for _ in 0..vlen {
 137                                         ret.push(match Readable::read(reader)? {
 138                                                 0u8 => None,
 139                                                 1u8 => Some((<u64 as Readable>::read(reader)? as usize, Readable::read(reader)?)),
 140                                                 _ => return Err(DecodeError::InvalidValue)
 141                                         });
 142                                 }
 143                                 Ok(Some(ret))
 144                         },
 145                         _ => Err(DecodeError::InvalidValue),
 146                 }
 147         }
 148 }
 149
 150 impl Writeable for Option<Vec<Option<(usize, Signature)>>> {
 151         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 152                 match self {
 153                         &Some(ref vec) => {
 154                                 1u8.write(writer)?;
 155                                 (vec.len() as u64).write(writer)?;
 156                                 for opt in vec.iter() {
 157                                         match opt {
 158                                                 &Some((ref idx, ref sig)) => {
 159                                                         1u8.write(writer)?;
 160                                                         (*idx as u64).write(writer)?;
 161                                                         sig.write(writer)?;
 162                                                 },
 163                                                 &None => 0u8.write(writer)?,
 164                                         }
 165                                 }
 166                         },
 167                         &None => 0u8.write(writer)?,
 168                 }
 169                 Ok(())
 170         }
 171 }
 172
 173 /// The claim commonly referred to as the pre-signed second-stage HTLC transaction.
 174 #[derive(Clone, PartialEq, Eq)]
 175 pub(crate) struct ExternalHTLCClaim {
 176         pub(crate) commitment_txid: Txid,
 177         pub(crate) per_commitment_number: u64,
 178         pub(crate) htlc: HTLCOutputInCommitment,
 179         pub(crate) preimage: Option<PaymentPreimage>,
 180         pub(crate) counterparty_sig: Signature,
 181 }
 182
 183 // Represents the different types of claims for which events are yielded externally to satisfy said
 184 // claims.
 185 #[derive(Clone, PartialEq, Eq)]
 186 pub(crate) enum ClaimEvent {
 187         /// Event yielded to signal that the commitment transaction fee must be bumped to claim any
 188         /// encumbered funds and proceed to HTLC resolution, if any HTLCs exist.
 189         BumpCommitment {
 190                 package_target_feerate_sat_per_1000_weight: u32,
 191                 commitment_tx: Transaction,
 192                 anchor_output_idx: u32,
 193         },
 194         /// Event yielded to signal that the commitment transaction has confirmed and its HTLCs must be
 195         /// resolved by broadcasting a transaction with sufficient fee to claim them.
 196         BumpHTLC {
 197                 target_feerate_sat_per_1000_weight: u32,
 198                 htlcs: Vec<ExternalHTLCClaim>,
 199                 tx_lock_time: LockTime,
 200         },
 201 }
 202
 203 /// Represents the different ways an output can be claimed (i.e., spent to an address under our
 204 /// control) onchain.
 205 pub(crate) enum OnchainClaim {
 206         /// A finalized transaction pending confirmation spending the output to claim.
 207         Tx(Transaction),
 208         /// An event yielded externally to signal additional inputs must be added to a transaction
 209         /// pending confirmation spending the output to claim.
 210         Event(ClaimEvent),
 211 }
 212
 213 /// OnchainTxHandler receives claiming requests, aggregates them if it's sound, broadcast and
 214 /// do RBF bumping if possible.
 215 #[derive(Clone)]
 216 pub struct OnchainTxHandler<ChannelSigner: WriteableEcdsaChannelSigner> {
 217         channel_value_satoshis: u64,
 218         channel_keys_id: [u8; 32],
 219         destination_script: ScriptBuf,
 220         holder_commitment: HolderCommitmentTransaction,
 221         prev_holder_commitment: Option<HolderCommitmentTransaction>,
 222
 223         pub(super) signer: ChannelSigner,
 224         pub(crate) channel_transaction_parameters: ChannelTransactionParameters,
 225
 226         // Used to track claiming requests. If claim tx doesn't confirm before height timer expiration we need to bump
 227         // it (RBF or CPFP). If an input has been part of an aggregate tx at first claim try, we need to keep it within
 228         // another bumped aggregate tx to comply with RBF rules. We may have multiple claiming txn in the flight for the
 229         // same set of outpoints. One of the outpoints may be spent by a transaction not issued by us. That's why at
 230         // block connection we scan all inputs and if any of them is among a set of a claiming request we test for set
 231         // equality between spending transaction and claim request. If true, it means transaction was one our claiming one
 232         // after a security delay of 6 blocks we remove pending claim request. If false, it means transaction wasn't and
 233         // we need to regenerate new claim request with reduced set of still-claimable outpoints.
 234         // Key is identifier of the pending claim request, i.e the txid of the initial claiming transaction generated by
 235         // us and is immutable until all outpoint of the claimable set are post-anti-reorg-delay solved.
 236         // Entry is cache of elements need to generate a bumped claiming transaction (see ClaimTxBumpMaterial)
 237         #[cfg(test)] // Used in functional_test to verify sanitization
 238         pub(crate) pending_claim_requests: HashMap<ClaimId, PackageTemplate>,
 239         #[cfg(not(test))]
 240         pending_claim_requests: HashMap<ClaimId, PackageTemplate>,
 241
 242         // Used to track external events that need to be forwarded to the `ChainMonitor`. This `Vec`
 243         // essentially acts as an insertion-ordered `HashMap` – there should only ever be one occurrence
 244         // of a `ClaimId`, which tracks its latest `ClaimEvent`, i.e., if a pending claim exists, and
 245         // a new block has been connected, resulting in a new claim, the previous will be replaced with
 246         // the new.
 247         //
 248         // These external events may be generated in the following cases:
 249         //      - A channel has been force closed by broadcasting the holder's latest commitment transaction
 250         //      - A block being connected/disconnected
 251         //      - Learning the preimage for an HTLC we can claim onchain
 252         pending_claim_events: Vec<(ClaimId, ClaimEvent)>,
 253
 254         // Used to link outpoints claimed in a connected block to a pending claim request. The keys
 255         // represent the outpoints that our `ChannelMonitor` has detected we have keys/scripts to
 256         // claim. The values track the pending claim request identifier and the initial confirmation
 257         // block height, and are immutable until the outpoint has enough confirmations to meet our
 258         // [`ANTI_REORG_DELAY`]. The initial confirmation block height is used to remove the entry if
 259         // the block gets disconnected.
 260         #[cfg(test)] // Used in functional_test to verify sanitization
 261         pub claimable_outpoints: HashMap<BitcoinOutPoint, (ClaimId, u32)>,
 262         #[cfg(not(test))]
 263         claimable_outpoints: HashMap<BitcoinOutPoint, (ClaimId, u32)>,
 264
 265         locktimed_packages: BTreeMap<u32, Vec<PackageTemplate>>,
 266
 267         onchain_events_awaiting_threshold_conf: Vec<OnchainEventEntry>,
 268
 269         pub(super) secp_ctx: Secp256k1<secp256k1::All>,
 270 }
 271
 272 impl<ChannelSigner: WriteableEcdsaChannelSigner> PartialEq for OnchainTxHandler<ChannelSigner> {
 273         fn eq(&self, other: &Self) -> bool {
 274                 // `signer`, `secp_ctx`, and `pending_claim_events` are excluded on purpose.
 275                 self.channel_value_satoshis == other.channel_value_satoshis &&
 276                         self.channel_keys_id == other.channel_keys_id &&
 277                         self.destination_script == other.destination_script &&
 278                         self.holder_commitment == other.holder_commitment &&
 279                         self.prev_holder_commitment == other.prev_holder_commitment &&
 280                         self.channel_transaction_parameters == other.channel_transaction_parameters &&
 281                         self.pending_claim_requests == other.pending_claim_requests &&
 282                         self.claimable_outpoints == other.claimable_outpoints &&
 283                         self.locktimed_packages == other.locktimed_packages &&
 284                         self.onchain_events_awaiting_threshold_conf == other.onchain_events_awaiting_threshold_conf
 285         }
 286 }
 287
 288 const SERIALIZATION_VERSION: u8 = 1;
 289 const MIN_SERIALIZATION_VERSION: u8 = 1;
 290
 291 impl<ChannelSigner: WriteableEcdsaChannelSigner> OnchainTxHandler<ChannelSigner> {
 292         pub(crate) fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 293                 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
 294
 295                 self.destination_script.write(writer)?;
 296                 self.holder_commitment.write(writer)?;
 297                 None::<Option<Vec<Option<(usize, Signature)>>>>.write(writer)?; // holder_htlc_sigs
 298                 self.prev_holder_commitment.write(writer)?;
 299                 None::<Option<Vec<Option<(usize, Signature)>>>>.write(writer)?; // prev_holder_htlc_sigs
 300
 301                 self.channel_transaction_parameters.write(writer)?;
 302
 303                 let mut key_data = VecWriter(Vec::new());
 304                 self.signer.write(&mut key_data)?;
 305                 assert!(key_data.0.len() < core::usize::MAX);
 306                 assert!(key_data.0.len() < core::u32::MAX as usize);
 307                 (key_data.0.len() as u32).write(writer)?;
 308                 writer.write_all(&key_data.0[..])?;
 309
 310                 writer.write_all(&(self.pending_claim_requests.len() as u64).to_be_bytes())?;
 311                 for (ref ancestor_claim_txid, request) in self.pending_claim_requests.iter() {
 312                         ancestor_claim_txid.write(writer)?;
 313                         request.write(writer)?;
 314                 }
 315
 316                 writer.write_all(&(self.claimable_outpoints.len() as u64).to_be_bytes())?;
 317                 for (ref outp, ref claim_and_height) in self.claimable_outpoints.iter() {
 318                         outp.write(writer)?;
 319                         claim_and_height.0.write(writer)?;
 320                         claim_and_height.1.write(writer)?;
 321                 }
 322
 323                 writer.write_all(&(self.locktimed_packages.len() as u64).to_be_bytes())?;
 324                 for (ref locktime, ref packages) in self.locktimed_packages.iter() {
 325                         locktime.write(writer)?;
 326                         writer.write_all(&(packages.len() as u64).to_be_bytes())?;
 327                         for ref package in packages.iter() {
 328                                 package.write(writer)?;
 329                         }
 330                 }
 331
 332                 writer.write_all(&(self.onchain_events_awaiting_threshold_conf.len() as u64).to_be_bytes())?;
 333                 for ref entry in self.onchain_events_awaiting_threshold_conf.iter() {
 334                         entry.write(writer)?;
 335                 }
 336
 337                 write_tlv_fields!(writer, {});
 338                 Ok(())
 339         }
 340 }
 341
 342 impl<'a, 'b, ES: EntropySource, SP: SignerProvider> ReadableArgs<(&'a ES, &'b SP, u64, [u8; 32])> for OnchainTxHandler<SP::EcdsaSigner> {
 343         fn read<R: io::Read>(reader: &mut R, args: (&'a ES, &'b SP, u64, [u8; 32])) -> Result<Self, DecodeError> {
 344                 let entropy_source = args.0;
 345                 let signer_provider = args.1;
 346                 let channel_value_satoshis = args.2;
 347                 let channel_keys_id = args.3;
 348
 349                 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
 350
 351                 let destination_script = Readable::read(reader)?;
 352
 353                 let holder_commitment = Readable::read(reader)?;
 354                 let _holder_htlc_sigs: Option<Vec<Option<(usize, Signature)>>> = Readable::read(reader)?;
 355                 let prev_holder_commitment = Readable::read(reader)?;
 356                 let _prev_holder_htlc_sigs: Option<Vec<Option<(usize, Signature)>>> = Readable::read(reader)?;
 357
 358                 let channel_parameters = Readable::read(reader)?;
 359
 360                 // Read the serialized signer bytes, but don't deserialize them, as we'll obtain our signer
 361                 // by re-deriving the private key material.
 362                 let keys_len: u32 = Readable::read(reader)?;
 363                 let mut bytes_read = 0;
 364                 while bytes_read != keys_len as usize {
 365                         // Read 1KB at a time to avoid accidentally allocating 4GB on corrupted channel keys
 366                         let mut data = [0; 1024];
 367                         let bytes_to_read = cmp::min(1024, keys_len as usize - bytes_read);
 368                         let read_slice = &mut data[0..bytes_to_read];
 369                         reader.read_exact(read_slice)?;
 370                         bytes_read += bytes_to_read;
 371                 }
 372
 373                 let mut signer = signer_provider.derive_channel_signer(channel_value_satoshis, channel_keys_id);
 374                 signer.provide_channel_parameters(&channel_parameters);
 375
 376                 let pending_claim_requests_len: u64 = Readable::read(reader)?;
 377                 let mut pending_claim_requests = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
 378                 for _ in 0..pending_claim_requests_len {
 379                         pending_claim_requests.insert(Readable::read(reader)?, Readable::read(reader)?);
 380                 }
 381
 382                 let claimable_outpoints_len: u64 = Readable::read(reader)?;
 383                 let mut claimable_outpoints = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
 384                 for _ in 0..claimable_outpoints_len {
 385                         let outpoint = Readable::read(reader)?;
 386                         let ancestor_claim_txid = Readable::read(reader)?;
 387                         let height = Readable::read(reader)?;
 388                         claimable_outpoints.insert(outpoint, (ancestor_claim_txid, height));
 389                 }
 390
 391                 let locktimed_packages_len: u64 = Readable::read(reader)?;
 392                 let mut locktimed_packages = BTreeMap::new();
 393                 for _ in 0..locktimed_packages_len {
 394                         let locktime = Readable::read(reader)?;
 395                         let packages_len: u64 = Readable::read(reader)?;
 396                         let mut packages = Vec::with_capacity(cmp::min(packages_len as usize, MAX_ALLOC_SIZE / core::mem::size_of::<PackageTemplate>()));
 397                         for _ in 0..packages_len {
 398                                 packages.push(Readable::read(reader)?);
 399                         }
 400                         locktimed_packages.insert(locktime, packages);
 401                 }
 402
 403                 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
 404                 let mut onchain_events_awaiting_threshold_conf = Vec::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
 405                 for _ in 0..waiting_threshold_conf_len {
 406                         if let Some(val) = MaybeReadable::read(reader)? {
 407                                 onchain_events_awaiting_threshold_conf.push(val);
 408                         }
 409                 }
 410
 411                 read_tlv_fields!(reader, {});
 412
 413                 let mut secp_ctx = Secp256k1::new();
 414                 secp_ctx.seeded_randomize(&entropy_source.get_secure_random_bytes());
 415
 416                 Ok(OnchainTxHandler {
 417                         channel_value_satoshis,
 418                         channel_keys_id,
 419                         destination_script,
 420                         holder_commitment,
 421                         prev_holder_commitment,
 422                         signer,
 423                         channel_transaction_parameters: channel_parameters,
 424                         claimable_outpoints,
 425                         locktimed_packages,
 426                         pending_claim_requests,
 427                         onchain_events_awaiting_threshold_conf,
 428                         pending_claim_events: Vec::new(),
 429                         secp_ctx,
 430                 })
 431         }
 432 }
 433
 434 impl<ChannelSigner: WriteableEcdsaChannelSigner> OnchainTxHandler<ChannelSigner> {
 435         pub(crate) fn new(
 436                 channel_value_satoshis: u64, channel_keys_id: [u8; 32], destination_script: ScriptBuf,
 437                 signer: ChannelSigner, channel_parameters: ChannelTransactionParameters,
 438                 holder_commitment: HolderCommitmentTransaction, secp_ctx: Secp256k1<secp256k1::All>
 439         ) -> Self {
 440                 OnchainTxHandler {
 441                         channel_value_satoshis,
 442                         channel_keys_id,
 443                         destination_script,
 444                         holder_commitment,
 445                         prev_holder_commitment: None,
 446                         signer,
 447                         channel_transaction_parameters: channel_parameters,
 448                         pending_claim_requests: HashMap::new(),
 449                         claimable_outpoints: HashMap::new(),
 450                         locktimed_packages: BTreeMap::new(),
 451                         onchain_events_awaiting_threshold_conf: Vec::new(),
 452                         pending_claim_events: Vec::new(),
 453                         secp_ctx,
 454                 }
 455         }
 456
 457         pub(crate) fn get_prev_holder_commitment_to_self_value(&self) -> Option<u64> {
 458                 self.prev_holder_commitment.as_ref().map(|commitment| commitment.to_broadcaster_value_sat())
 459         }
 460
 461         pub(crate) fn get_cur_holder_commitment_to_self_value(&self) -> u64 {
 462                 self.holder_commitment.to_broadcaster_value_sat()
 463         }
 464
 465         pub(crate) fn get_and_clear_pending_claim_events(&mut self) -> Vec<(ClaimId, ClaimEvent)> {
 466                 let mut events = Vec::new();
 467                 swap(&mut events, &mut self.pending_claim_events);
 468                 events
 469         }
 470
 471         /// Triggers rebroadcasts/fee-bumps of pending claims from a force-closed channel. This is
 472         /// crucial in preventing certain classes of pinning attacks, detecting substantial mempool
 473         /// feerate changes between blocks, and ensuring reliability if broadcasting fails. We recommend
 474         /// invoking this every 30 seconds, or lower if running in an environment with spotty
 475         /// connections, like on mobile.
 476         pub(super) fn rebroadcast_pending_claims<B: Deref, F: Deref, L: Logger>(
 477                 &mut self, current_height: u32, broadcaster: &B, fee_estimator: &LowerBoundedFeeEstimator<F>,
 478                 logger: &L,
 479         )
 480         where
 481                 B::Target: BroadcasterInterface,
 482                 F::Target: FeeEstimator,
 483         {
 484                 let mut bump_requests = Vec::with_capacity(self.pending_claim_requests.len());
 485                 for (claim_id, request) in self.pending_claim_requests.iter() {
 486                         let inputs = request.outpoints();
 487                         log_info!(logger, "Triggering rebroadcast/fee-bump for request with inputs {:?}", inputs);
 488                         bump_requests.push((*claim_id, request.clone()));
 489                 }
 490                 for (claim_id, request) in bump_requests {
 491                         self.generate_claim(current_height, &request, false /* force_feerate_bump */, fee_estimator, logger)
 492                                 .map(|(_, new_feerate, claim)| {
 493                                         let mut bumped_feerate = false;
 494                                         if let Some(mut_request) = self.pending_claim_requests.get_mut(&claim_id) {
 495                                                 bumped_feerate = request.previous_feerate() > new_feerate;
 496                                                 mut_request.set_feerate(new_feerate);
 497                                         }
 498                                         match claim {
 499                                                 OnchainClaim::Tx(tx) => {
 500                                                         let log_start = if bumped_feerate { "Broadcasting RBF-bumped" } else { "Rebroadcasting" };
 501                                                         log_info!(logger, "{} onchain {}", log_start, log_tx!(tx));
 502                                                         broadcaster.broadcast_transactions(&[&tx]);
 503                                                 },
 504                                                 OnchainClaim::Event(event) => {
 505                                                         let log_start = if bumped_feerate { "Yielding fee-bumped" } else { "Replaying" };
 506                                                         log_info!(logger, "{} onchain event to spend inputs {:?}", log_start,
 507                                                                 request.outpoints());
 508                                                         #[cfg(debug_assertions)] {
 509                                                                 debug_assert!(request.requires_external_funding());
 510                                                                 let num_existing = self.pending_claim_events.iter()
 511                                                                         .filter(|entry| entry.0 == claim_id).count();
 512                                                                 assert!(num_existing == 0 || num_existing == 1);
 513                                                         }
 514                                                         self.pending_claim_events.retain(|event| event.0 != claim_id);
 515                                                         self.pending_claim_events.push((claim_id, event));
 516                                                 }
 517                                         }
 518                                 });
 519                 }
 520         }
 521
 522         /// Lightning security model (i.e being able to redeem/timeout HTLC or penalize counterparty
 523         /// onchain) lays on the assumption of claim transactions getting confirmed before timelock
 524         /// expiration (CSV or CLTV following cases). In case of high-fee spikes, claim tx may get stuck
 525         /// in the mempool, so you need to bump its feerate quickly using Replace-By-Fee or
 526         /// Child-Pay-For-Parent.
 527         ///
 528         /// Panics if there are signing errors, because signing operations in reaction to on-chain
 529         /// events are not expected to fail, and if they do, we may lose funds.
 530         fn generate_claim<F: Deref, L: Logger>(
 531                 &mut self, cur_height: u32, cached_request: &PackageTemplate, force_feerate_bump: bool,
 532                 fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L,
 533         ) -> Option<(u32, u64, OnchainClaim)>
 534         where F::Target: FeeEstimator,
 535         {
 536                 let request_outpoints = cached_request.outpoints();
 537                 if request_outpoints.is_empty() {
 538                         // Don't prune pending claiming request yet, we may have to resurrect HTLCs. Untractable
 539                         // packages cannot be aggregated and will never be split, so we cannot end up with an
 540                         // empty claim.
 541                         debug_assert!(cached_request.is_malleable());
 542                         return None;
 543                 }
 544                 // If we've seen transaction inclusion in the chain for all outpoints in our request, we
 545                 // don't need to continue generating more claims. We'll keep tracking the request to fully
 546                 // remove it once it reaches the confirmation threshold, or to generate a new claim if the
 547                 // transaction is reorged out.
 548                 let mut all_inputs_have_confirmed_spend = true;
 549                 for outpoint in request_outpoints.iter() {
 550                         if let Some((request_claim_id, _)) = self.claimable_outpoints.get(*outpoint) {
 551                                 // We check for outpoint spends within claims individually rather than as a set
 552                                 // since requests can have outpoints split off.
 553                                 if !self.onchain_events_awaiting_threshold_conf.iter()
 554                                         .any(|event_entry| if let OnchainEvent::Claim { claim_id } = event_entry.event {
 555                                                 *request_claim_id == claim_id
 556                                         } else {
 557                                                 // The onchain event is not a claim, keep seeking until we find one.
 558                                                 false
 559                                         })
 560                                 {
 561                                         // Either we had no `OnchainEvent::Claim`, or we did but none matched the
 562                                         // outpoint's registered spend.
 563                                         all_inputs_have_confirmed_spend = false;
 564                                 }
 565                         } else {
 566                                 // The request's outpoint spend does not exist yet.
 567                                 all_inputs_have_confirmed_spend = false;
 568                         }
 569                 }
 570                 if all_inputs_have_confirmed_spend {
 571                         return None;
 572                 }
 573
 574                 // Compute new height timer to decide when we need to regenerate a new bumped version of the claim tx (if we
 575                 // didn't receive confirmation of it before, or not enough reorg-safe depth on top of it).
 576                 let new_timer = cached_request.get_height_timer(cur_height);
 577                 if cached_request.is_malleable() {
 578                         if cached_request.requires_external_funding() {
 579                                 let target_feerate_sat_per_1000_weight = cached_request.compute_package_feerate(
 580                                         fee_estimator, ConfirmationTarget::OnChainSweep, force_feerate_bump
 581                                 );
 582                                 if let Some(htlcs) = cached_request.construct_malleable_package_with_external_funding(self) {
 583                                         return Some((
 584                                                 new_timer,
 585                                                 target_feerate_sat_per_1000_weight as u64,
 586                                                 OnchainClaim::Event(ClaimEvent::BumpHTLC {
 587                                                         target_feerate_sat_per_1000_weight,
 588                                                         htlcs,
 589                                                         tx_lock_time: LockTime::from_consensus(cached_request.package_locktime(cur_height)),
 590                                                 }),
 591                                         ));
 592                                 } else {
 593                                         return None;
 594                                 }
 595                         }
 596
 597                         let predicted_weight = cached_request.package_weight(&self.destination_script);
 598                         if let Some((output_value, new_feerate)) = cached_request.compute_package_output(
 599                                 predicted_weight, self.destination_script.dust_value().to_sat(),
 600                                 force_feerate_bump, fee_estimator, logger,
 601                         ) {
 602                                 assert!(new_feerate != 0);
 603
 604                                 let transaction = cached_request.finalize_malleable_package(
 605                                         cur_height, self, output_value, self.destination_script.clone(), logger
 606                                 ).unwrap();
 607                                 log_trace!(logger, "...with timer {} and feerate {}", new_timer, new_feerate);
 608                                 assert!(predicted_weight >= transaction.weight().to_wu());
 609                                 return Some((new_timer, new_feerate, OnchainClaim::Tx(transaction)));
 610                         }
 611                 } else {
 612                         // Untractable packages cannot have their fees bumped through Replace-By-Fee. Some
 613                         // packages may support fee bumping through Child-Pays-For-Parent, indicated by those
 614                         // which require external funding.
 615                         let mut inputs = cached_request.inputs();
 616                         debug_assert_eq!(inputs.len(), 1);
 617                         let tx = match cached_request.finalize_untractable_package(self, logger) {
 618                                 Some(tx) => tx,
 619                                 None => return None,
 620                         };
 621                         if !cached_request.requires_external_funding() {
 622                                 return Some((new_timer, 0, OnchainClaim::Tx(tx)));
 623                         }
 624                         return inputs.find_map(|input| match input {
 625                                 // Commitment inputs with anchors support are the only untractable inputs supported
 626                                 // thus far that require external funding.
 627                                 PackageSolvingData::HolderFundingOutput(output) => {
 628                                         debug_assert_eq!(tx.txid(), self.holder_commitment.trust().txid(),
 629                                                 "Holder commitment transaction mismatch");
 630
 631                                         let conf_target = ConfirmationTarget::OnChainSweep;
 632                                         let package_target_feerate_sat_per_1000_weight = cached_request
 633                                                 .compute_package_feerate(fee_estimator, conf_target, force_feerate_bump);
 634                                         if let Some(input_amount_sat) = output.funding_amount {
 635                                                 let fee_sat = input_amount_sat - tx.output.iter().map(|output| output.value).sum::<u64>();
 636                                                 let commitment_tx_feerate_sat_per_1000_weight =
 637                                                         compute_feerate_sat_per_1000_weight(fee_sat, tx.weight().to_wu());
 638                                                 if commitment_tx_feerate_sat_per_1000_weight >= package_target_feerate_sat_per_1000_weight {
 639                                                         log_debug!(logger, "Pre-signed {} already has feerate {} sat/kW above required {} sat/kW",
 640                                                                 log_tx!(tx), commitment_tx_feerate_sat_per_1000_weight,
 641                                                                 package_target_feerate_sat_per_1000_weight);
 642                                                         return Some((new_timer, 0, OnchainClaim::Tx(tx.clone())));
 643                                                 }
 644                                         }
 645
 646                                         // We'll locate an anchor output we can spend within the commitment transaction.
 647                                         let funding_pubkey = &self.channel_transaction_parameters.holder_pubkeys.funding_pubkey;
 648                                         match chan_utils::get_anchor_output(&tx, funding_pubkey) {
 649                                                 // An anchor output was found, so we should yield a funding event externally.
 650                                                 Some((idx, _)) => {
 651                                                         // TODO: Use a lower confirmation target when both our and the
 652                                                         // counterparty's latest commitment don't have any HTLCs present.
 653                                                         Some((
 654                                                                 new_timer,
 655                                                                 package_target_feerate_sat_per_1000_weight as u64,
 656                                                                 OnchainClaim::Event(ClaimEvent::BumpCommitment {
 657                                                                         package_target_feerate_sat_per_1000_weight,
 658                                                                         commitment_tx: tx.clone(),
 659                                                                         anchor_output_idx: idx,
 660                                                                 }),
 661                                                         ))
 662                                                 },
 663                                                 // An anchor output was not found. There's nothing we can do other than
 664                                                 // attempt to broadcast the transaction with its current fee rate and hope
 665                                                 // it confirms. This is essentially the same behavior as a commitment
 666                                                 // transaction without anchor outputs.
 667                                                 None => Some((new_timer, 0, OnchainClaim::Tx(tx.clone()))),
 668                                         }
 669                                 },
 670                                 _ => {
 671                                         debug_assert!(false, "Only HolderFundingOutput inputs should be untractable and require external funding");
 672                                         None
 673                                 },
 674                         })
 675                 }
 676                 None
 677         }
 678
 679         pub fn abandon_claim(&mut self, outpoint: &BitcoinOutPoint) {
 680                 let claim_id = self.claimable_outpoints.get(outpoint).map(|(claim_id, _)| *claim_id)
 681                         .or_else(|| {
 682                                 self.pending_claim_requests.iter()
 683                                         .find(|(_, claim)| claim.outpoints().iter().any(|claim_outpoint| *claim_outpoint == outpoint))
 684                                         .map(|(claim_id, _)| *claim_id)
 685                         });
 686                 if let Some(claim_id) = claim_id {
 687                         if let Some(claim) = self.pending_claim_requests.remove(&claim_id) {
 688                                 for outpoint in claim.outpoints() {
 689                                         self.claimable_outpoints.remove(&outpoint);
 690                                 }
 691                         }
 692                 } else {
 693                         self.locktimed_packages.values_mut().for_each(|claims|
 694                                 claims.retain(|claim| !claim.outpoints().iter().any(|claim_outpoint| *claim_outpoint == outpoint)));
 695                 }
 696         }
 697
 698         /// Upon channelmonitor.block_connected(..) or upon provision of a preimage on the forward link
 699         /// for this channel, provide new relevant on-chain transactions and/or new claim requests.
 700         /// Together with `update_claims_view_from_matched_txn` this used to be named
 701         /// `block_connected`, but it is now also used for claiming an HTLC output if we receive a
 702         /// preimage after force-close.
 703         ///
 704         /// `conf_height` represents the height at which the request was generated. This
 705         /// does not need to equal the current blockchain tip height, which should be provided via
 706         /// `cur_height`, however it must never be higher than `cur_height`.
 707         pub(super) fn update_claims_view_from_requests<B: Deref, F: Deref, L: Logger>(
 708                 &mut self, requests: Vec<PackageTemplate>, conf_height: u32, cur_height: u32,
 709                 broadcaster: &B, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L
 710         ) where
 711                 B::Target: BroadcasterInterface,
 712                 F::Target: FeeEstimator,
 713         {
 714                 log_debug!(logger, "Updating claims view at height {} with {} claim requests", cur_height, requests.len());
 715                 let mut preprocessed_requests = Vec::with_capacity(requests.len());
 716                 let mut aggregated_request = None;
 717
 718                 // Try to aggregate outputs if their timelock expiration isn't imminent (package timelock
 719                 // <= CLTV_SHARED_CLAIM_BUFFER) and they don't require an immediate nLockTime (aggregable).
 720                 for req in requests {
 721                         // Don't claim a outpoint twice that would be bad for privacy and may uselessly lock a CPFP input for a while
 722                         if let Some(_) = self.claimable_outpoints.get(req.outpoints()[0]) {
 723                                 log_info!(logger, "Ignoring second claim for outpoint {}:{}, already registered its claiming request", req.outpoints()[0].txid, req.outpoints()[0].vout);
 724                         } else {
 725                                 let timelocked_equivalent_package = self.locktimed_packages.iter().map(|v| v.1.iter()).flatten()
 726                                         .find(|locked_package| locked_package.outpoints() == req.outpoints());
 727                                 if let Some(package) = timelocked_equivalent_package {
 728                                         log_info!(logger, "Ignoring second claim for outpoint {}:{}, we already have one which we're waiting on a timelock at {} for.",
 729                                                 req.outpoints()[0].txid, req.outpoints()[0].vout, package.package_locktime(cur_height));
 730                                         continue;
 731                                 }
 732
 733                                 let package_locktime = req.package_locktime(cur_height);
 734                                 if package_locktime > cur_height + 1 {
 735                                         log_info!(logger, "Delaying claim of package until its timelock at {} (current height {}), the following outpoints are spent:", package_locktime, cur_height);
 736                                         for outpoint in req.outpoints() {
 737                                                 log_info!(logger, "  Outpoint {}", outpoint);
 738                                         }
 739                                         self.locktimed_packages.entry(package_locktime).or_insert(Vec::new()).push(req);
 740                                         continue;
 741                                 }
 742
 743                                 log_trace!(logger, "Test if outpoint can be aggregated with expiration {} against {}", req.timelock(), cur_height + CLTV_SHARED_CLAIM_BUFFER);
 744                                 if req.timelock() <= cur_height + CLTV_SHARED_CLAIM_BUFFER || !req.aggregable() {
 745                                         // Don't aggregate if outpoint package timelock is soon or marked as non-aggregable
 746                                         preprocessed_requests.push(req);
 747                                 } else if aggregated_request.is_none() {
 748                                         aggregated_request = Some(req);
 749                                 } else {
 750                                         aggregated_request.as_mut().unwrap().merge_package(req);
 751                                 }
 752                         }
 753                 }
 754                 if let Some(req) = aggregated_request {
 755                         preprocessed_requests.push(req);
 756                 }
 757
 758                 // Claim everything up to and including `cur_height`
 759                 let remaining_locked_packages = self.locktimed_packages.split_off(&(cur_height + 1));
 760                 for (pop_height, mut entry) in self.locktimed_packages.iter_mut() {
 761                         log_trace!(logger, "Restoring delayed claim of package(s) at their timelock at {}.", pop_height);
 762                         preprocessed_requests.append(&mut entry);
 763                 }
 764                 self.locktimed_packages = remaining_locked_packages;
 765
 766                 // Generate claim transactions and track them to bump if necessary at
 767                 // height timer expiration (i.e in how many blocks we're going to take action).
 768                 for mut req in preprocessed_requests {
 769                         if let Some((new_timer, new_feerate, claim)) = self.generate_claim(
 770                                 cur_height, &req, true /* force_feerate_bump */, &*fee_estimator, &*logger,
 771                         ) {
 772                                 req.set_timer(new_timer);
 773                                 req.set_feerate(new_feerate);
 774                                 // Once a pending claim has an id assigned, it remains fixed until the claim is
 775                                 // satisfied, regardless of whether the claim switches between different variants of
 776                                 // `OnchainClaim`.
 777                                 let claim_id = match claim {
 778                                         OnchainClaim::Tx(tx) => {
 779                                                 log_info!(logger, "Broadcasting onchain {}", log_tx!(tx));
 780                                                 broadcaster.broadcast_transactions(&[&tx]);
 781                                                 ClaimId(tx.txid().to_byte_array())
 782                                         },
 783                                         OnchainClaim::Event(claim_event) => {
 784                                                 log_info!(logger, "Yielding onchain event to spend inputs {:?}", req.outpoints());
 785                                                 let claim_id = match claim_event {
 786                                                         ClaimEvent::BumpCommitment { ref commitment_tx, .. } =>
 787                                                                 // For commitment claims, we can just use their txid as it should
 788                                                                 // already be unique.
 789                                                                 ClaimId(commitment_tx.txid().to_byte_array()),
 790                                                         ClaimEvent::BumpHTLC { ref htlcs, .. } => {
 791                                                                 // For HTLC claims, commit to the entire set of HTLC outputs to
 792                                                                 // claim, which will always be unique per request. Once a claim ID
 793                                                                 // is generated, it is assigned and remains unchanged, even if the
 794                                                                 // underlying set of HTLCs changes.
 795                                                                 let mut engine = Sha256::engine();
 796                                                                 for htlc in htlcs {
 797                                                                         engine.input(&htlc.commitment_txid.to_byte_array());
 798                                                                         engine.input(&htlc.htlc.transaction_output_index.unwrap().to_be_bytes());
 799                                                                 }
 800                                                                 ClaimId(Sha256::from_engine(engine).to_byte_array())
 801                                                         },
 802                                                 };
 803                                                 debug_assert!(self.pending_claim_requests.get(&claim_id).is_none());
 804                                                 debug_assert_eq!(self.pending_claim_events.iter().filter(|entry| entry.0 == claim_id).count(), 0);
 805                                                 self.pending_claim_events.push((claim_id, claim_event));
 806                                                 claim_id
 807                                         },
 808                                 };
 809                                 // Because fuzzing can cause hash collisions, we can end up with conflicting claim
 810                                 // ids here, so we only assert when not fuzzing.
 811                                 debug_assert!(cfg!(fuzzing) || self.pending_claim_requests.get(&claim_id).is_none());
 812                                 for k in req.outpoints() {
 813                                         log_info!(logger, "Registering claiming request for {}:{}", k.txid, k.vout);
 814                                         self.claimable_outpoints.insert(k.clone(), (claim_id, conf_height));
 815                                 }
 816                                 self.pending_claim_requests.insert(claim_id, req);
 817                         }
 818                 }
 819         }
 820
 821         /// Upon channelmonitor.block_connected(..) or upon provision of a preimage on the forward link
 822         /// for this channel, provide new relevant on-chain transactions and/or new claim requests.
 823         /// Together with `update_claims_view_from_requests` this used to be named `block_connected`,
 824         /// but it is now also used for claiming an HTLC output if we receive a preimage after force-close.
 825         ///
 826         /// `conf_height` represents the height at which the transactions in `txn_matched` were
 827         /// confirmed. This does not need to equal the current blockchain tip height, which should be
 828         /// provided via `cur_height`, however it must never be higher than `cur_height`.
 829         pub(super) fn update_claims_view_from_matched_txn<B: Deref, F: Deref, L: Logger>(
 830                 &mut self, txn_matched: &[&Transaction], conf_height: u32, conf_hash: BlockHash,
 831                 cur_height: u32, broadcaster: &B, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L
 832         ) where
 833                 B::Target: BroadcasterInterface,
 834                 F::Target: FeeEstimator,
 835         {
 836                 log_debug!(logger, "Updating claims view at height {} with {} matched transactions in block {}", cur_height, txn_matched.len(), conf_height);
 837                 let mut bump_candidates = HashMap::new();
 838                 for tx in txn_matched {
 839                         // Scan all input to verify is one of the outpoint spent is of interest for us
 840                         let mut claimed_outputs_material = Vec::new();
 841                         for inp in &tx.input {
 842                                 if let Some((claim_id, _)) = self.claimable_outpoints.get(&inp.previous_output) {
 843                                         // If outpoint has claim request pending on it...
 844                                         if let Some(request) = self.pending_claim_requests.get_mut(claim_id) {
 845                                                 //... we need to verify equality between transaction outpoints and claim request
 846                                                 // outpoints to know if transaction is the original claim or a bumped one issued
 847                                                 // by us.
 848                                                 let mut are_sets_equal = true;
 849                                                 let mut tx_inputs = tx.input.iter().map(|input| &input.previous_output).collect::<Vec<_>>();
 850                                                 tx_inputs.sort_unstable();
 851                                                 for request_input in request.outpoints() {
 852                                                         if tx_inputs.binary_search(&request_input).is_err() {
 853                                                                 are_sets_equal = false;
 854                                                                 break;
 855                                                         }
 856                                                 }
 857
 858                                                 macro_rules! clean_claim_request_after_safety_delay {
 859                                                         () => {
 860                                                                 let entry = OnchainEventEntry {
 861                                                                         txid: tx.txid(),
 862                                                                         height: conf_height,
 863                                                                         block_hash: Some(conf_hash),
 864                                                                         event: OnchainEvent::Claim { claim_id: *claim_id }
 865                                                                 };
 866                                                                 if !self.onchain_events_awaiting_threshold_conf.contains(&entry) {
 867                                                                         self.onchain_events_awaiting_threshold_conf.push(entry);
 868                                                                 }
 869                                                         }
 870                                                 }
 871
 872                                                 // If this is our transaction (or our counterparty spent all the outputs
 873                                                 // before we could anyway with same inputs order than us), wait for
 874                                                 // ANTI_REORG_DELAY and clean the RBF tracking map.
 875                                                 if are_sets_equal {
 876                                                         clean_claim_request_after_safety_delay!();
 877                                                 } else { // If false, generate new claim request with update outpoint set
 878                                                         let mut at_least_one_drop = false;
 879                                                         for input in tx.input.iter() {
 880                                                                 if let Some(package) = request.split_package(&input.previous_output) {
 881                                                                         claimed_outputs_material.push(package);
 882                                                                         at_least_one_drop = true;
 883                                                                 }
 884                                                                 // If there are no outpoints left to claim in this request, drop it entirely after ANTI_REORG_DELAY.
 885                                                                 if request.outpoints().is_empty() {
 886                                                                         clean_claim_request_after_safety_delay!();
 887                                                                 }
 888                                                         }
 889                                                         //TODO: recompute soonest_timelock to avoid wasting a bit on fees
 890                                                         if at_least_one_drop {
 891                                                                 bump_candidates.insert(*claim_id, request.clone());
 892                                                                 // If we have any pending claim events for the request being updated
 893                                                                 // that have yet to be consumed, we'll remove them since they will
 894                                                                 // end up producing an invalid transaction by double spending
 895                                                                 // input(s) that already have a confirmed spend. If such spend is
 896                                                                 // reorged out of the chain, then we'll attempt to re-spend the
 897                                                                 // inputs once we see it.
 898                                                                 #[cfg(debug_assertions)] {
 899                                                                         let existing = self.pending_claim_events.iter()
 900                                                                                 .filter(|entry| entry.0 == *claim_id).count();
 901                                                                         assert!(existing == 0 || existing == 1);
 902                                                                 }
 903                                                                 self.pending_claim_events.retain(|entry| entry.0 != *claim_id);
 904                                                         }
 905                                                 }
 906                                                 break; //No need to iterate further, either tx is our or their
 907                                         } else {
 908                                                 panic!("Inconsistencies between pending_claim_requests map and claimable_outpoints map");
 909                                         }
 910                                 }
 911                         }
 912                         for package in claimed_outputs_material.drain(..) {
 913                                 let entry = OnchainEventEntry {
 914                                         txid: tx.txid(),
 915                                         height: conf_height,
 916                                         block_hash: Some(conf_hash),
 917                                         event: OnchainEvent::ContentiousOutpoint { package },
 918                                 };
 919                                 if !self.onchain_events_awaiting_threshold_conf.contains(&entry) {
 920                                         self.onchain_events_awaiting_threshold_conf.push(entry);
 921                                 }
 922                         }
 923                 }
 924
 925                 // After security delay, either our claim tx got enough confs or outpoint is definetely out of reach
 926                 let onchain_events_awaiting_threshold_conf =
 927                         self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
 928                 for entry in onchain_events_awaiting_threshold_conf {
 929                         if entry.has_reached_confirmation_threshold(cur_height) {
 930                                 match entry.event {
 931                                         OnchainEvent::Claim { claim_id } => {
 932                                                 // We may remove a whole set of claim outpoints here, as these one may have
 933                                                 // been aggregated in a single tx and claimed so atomically
 934                                                 if let Some(request) = self.pending_claim_requests.remove(&claim_id) {
 935                                                         for outpoint in request.outpoints() {
 936                                                                 log_debug!(logger, "Removing claim tracking for {} due to maturation of claim package {}.",
 937                                                                         outpoint, log_bytes!(claim_id.0));
 938                                                                 self.claimable_outpoints.remove(outpoint);
 939                                                         }
 940                                                         #[cfg(debug_assertions)] {
 941                                                                 let num_existing = self.pending_claim_events.iter()
 942                                                                         .filter(|entry| entry.0 == claim_id).count();
 943                                                                 assert!(num_existing == 0 || num_existing == 1);
 944                                                         }
 945                                                         self.pending_claim_events.retain(|(id, _)| *id != claim_id);
 946                                                 }
 947                                         },
 948                                         OnchainEvent::ContentiousOutpoint { package } => {
 949                                                 log_debug!(logger, "Removing claim tracking due to maturation of claim tx for outpoints:");
 950                                                 log_debug!(logger, " {:?}", package.outpoints());
 951                                                 self.claimable_outpoints.remove(package.outpoints()[0]);
 952                                         }
 953                                 }
 954                         } else {
 955                                 self.onchain_events_awaiting_threshold_conf.push(entry);
 956                         }
 957                 }
 958
 959                 // Check if any pending claim request must be rescheduled
 960                 for (claim_id, request) in self.pending_claim_requests.iter() {
 961                         if cur_height >= request.timer() {
 962                                 bump_candidates.insert(*claim_id, request.clone());
 963                         }
 964                 }
 965
 966                 // Build, bump and rebroadcast tx accordingly
 967                 log_trace!(logger, "Bumping {} candidates", bump_candidates.len());
 968                 for (claim_id, request) in bump_candidates.iter() {
 969                         if let Some((new_timer, new_feerate, bump_claim)) = self.generate_claim(
 970                                 cur_height, &request, true /* force_feerate_bump */, &*fee_estimator, &*logger,
 971                         ) {
 972                                 match bump_claim {
 973                                         OnchainClaim::Tx(bump_tx) => {
 974                                                 log_info!(logger, "Broadcasting RBF-bumped onchain {}", log_tx!(bump_tx));
 975                                                 broadcaster.broadcast_transactions(&[&bump_tx]);
 976                                         },
 977                                         OnchainClaim::Event(claim_event) => {
 978                                                 log_info!(logger, "Yielding RBF-bumped onchain event to spend inputs {:?}", request.outpoints());
 979                                                 #[cfg(debug_assertions)] {
 980                                                         let num_existing = self.pending_claim_events.iter().
 981                                                                 filter(|entry| entry.0 == *claim_id).count();
 982                                                         assert!(num_existing == 0 || num_existing == 1);
 983                                                 }
 984                                                 self.pending_claim_events.retain(|event| event.0 != *claim_id);
 985                                                 self.pending_claim_events.push((*claim_id, claim_event));
 986                                         },
 987                                 }
 988                                 if let Some(request) = self.pending_claim_requests.get_mut(claim_id) {
 989                                         request.set_timer(new_timer);
 990                                         request.set_feerate(new_feerate);
 991                                 }
 992                         }
 993                 }
 994         }
 995
 996         pub(super) fn transaction_unconfirmed<B: Deref, F: Deref, L: Logger>(
 997                 &mut self,
 998                 txid: &Txid,
 999                 broadcaster: B,
1000                 fee_estimator: &LowerBoundedFeeEstimator<F>,
1001                 logger: &L,
1002         ) where
1003                 B::Target: BroadcasterInterface,
1004                 F::Target: FeeEstimator,
1005         {
1006                 let mut height = None;
1007                 for entry in self.onchain_events_awaiting_threshold_conf.iter() {
1008                         if entry.txid == *txid {
1009                                 height = Some(entry.height);
1010                                 break;
1011                         }
1012                 }
1013
1014                 if let Some(height) = height {
1015                         self.block_disconnected(height, broadcaster, fee_estimator, logger);
1016                 }
1017         }
1018
1019         pub(super) fn block_disconnected<B: Deref, F: Deref, L: Logger>(&mut self, height: u32, broadcaster: B, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L)
1020                 where B::Target: BroadcasterInterface,
1021                         F::Target: FeeEstimator,
1022         {
1023                 let mut bump_candidates = HashMap::new();
1024                 let onchain_events_awaiting_threshold_conf =
1025                         self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
1026                 for entry in onchain_events_awaiting_threshold_conf {
1027                         if entry.height >= height {
1028                                 //- our claim tx on a commitment tx output
1029                                 //- resurect outpoint back in its claimable set and regenerate tx
1030                                 match entry.event {
1031                                         OnchainEvent::ContentiousOutpoint { package } => {
1032                                                 if let Some(pending_claim) = self.claimable_outpoints.get(package.outpoints()[0]) {
1033                                                         if let Some(request) = self.pending_claim_requests.get_mut(&pending_claim.0) {
1034                                                                 request.merge_package(package);
1035                                                                 // Using a HashMap guarantee us than if we have multiple outpoints getting
1036                                                                 // resurrected only one bump claim tx is going to be broadcast
1037                                                                 bump_candidates.insert(pending_claim.clone(), request.clone());
1038                                                         }
1039                                                 }
1040                                         },
1041                                         _ => {},
1042                                 }
1043                         } else {
1044                                 self.onchain_events_awaiting_threshold_conf.push(entry);
1045                         }
1046                 }
1047                 for ((_claim_id, _), ref mut request) in bump_candidates.iter_mut() {
1048                         // `height` is the height being disconnected, so our `current_height` is 1 lower.
1049                         let current_height = height - 1;
1050                         if let Some((new_timer, new_feerate, bump_claim)) = self.generate_claim(
1051                                 current_height, &request, true /* force_feerate_bump */, fee_estimator, logger
1052                         ) {
1053                                 request.set_timer(new_timer);
1054                                 request.set_feerate(new_feerate);
1055                                 match bump_claim {
1056                                         OnchainClaim::Tx(bump_tx) => {
1057                                                 log_info!(logger, "Broadcasting onchain {}", log_tx!(bump_tx));
1058                                                 broadcaster.broadcast_transactions(&[&bump_tx]);
1059                                         },
1060                                         OnchainClaim::Event(claim_event) => {
1061                                                 log_info!(logger, "Yielding onchain event after reorg to spend inputs {:?}", request.outpoints());
1062                                                 #[cfg(debug_assertions)] {
1063                                                         let num_existing = self.pending_claim_events.iter()
1064                                                                 .filter(|entry| entry.0 == *_claim_id).count();
1065                                                         assert!(num_existing == 0 || num_existing == 1);
1066                                                 }
1067                                                 self.pending_claim_events.retain(|event| event.0 != *_claim_id);
1068                                                 self.pending_claim_events.push((*_claim_id, claim_event));
1069                                         },
1070                                 }
1071                         }
1072                 }
1073                 for (ancestor_claim_txid, request) in bump_candidates.drain() {
1074                         self.pending_claim_requests.insert(ancestor_claim_txid.0, request);
1075                 }
1076                 //TODO: if we implement cross-block aggregated claim transaction we need to refresh set of outpoints and regenerate tx but
1077                 // right now if one of the outpoint get disconnected, just erase whole pending claim request.
1078                 let mut remove_request = Vec::new();
1079                 self.claimable_outpoints.retain(|_, ref v|
1080                         if v.1 >= height {
1081                         remove_request.push(v.0.clone());
1082                         false
1083                         } else { true });
1084                 for req in remove_request {
1085                         self.pending_claim_requests.remove(&req);
1086                 }
1087         }
1088
1089         pub(crate) fn is_output_spend_pending(&self, outpoint: &BitcoinOutPoint) -> bool {
1090                 self.claimable_outpoints.get(outpoint).is_some()
1091         }
1092
1093         pub(crate) fn get_relevant_txids(&self) -> Vec<(Txid, u32, Option<BlockHash>)> {
1094                 let mut txids: Vec<(Txid, u32, Option<BlockHash>)> = self.onchain_events_awaiting_threshold_conf
1095                         .iter()
1096                         .map(|entry| (entry.txid, entry.height, entry.block_hash))
1097                         .collect();
1098                 txids.sort_unstable_by(|a, b| a.0.cmp(&b.0).then(b.1.cmp(&a.1)));
1099                 txids.dedup_by_key(|(txid, _, _)| *txid);
1100                 txids
1101         }
1102
1103         pub(crate) fn provide_latest_holder_tx(&mut self, tx: HolderCommitmentTransaction) {
1104                 self.prev_holder_commitment = Some(replace(&mut self.holder_commitment, tx));
1105         }
1106
1107         pub(crate) fn get_unsigned_holder_commitment_tx(&self) -> &Transaction {
1108                 &self.holder_commitment.trust().built_transaction().transaction
1109         }
1110
1111         //TODO: getting lastest holder transactions should be infallible and result in us "force-closing the channel", but we may
1112         // have empty holder commitment transaction if a ChannelMonitor is asked to force-close just after OutboundV1Channel::get_funding_created,
1113         // before providing a initial commitment transaction. For outbound channel, init ChannelMonitor at Channel::funding_signed, there is nothing
1114         // to monitor before.
1115         pub(crate) fn get_fully_signed_holder_tx(&mut self, funding_redeemscript: &Script) -> Transaction {
1116                 let sig = self.signer.sign_holder_commitment(&self.holder_commitment, &self.secp_ctx).expect("signing holder commitment");
1117                 self.holder_commitment.add_holder_sig(funding_redeemscript, sig)
1118         }
1119
1120         #[cfg(any(test, feature="unsafe_revoked_tx_signing"))]
1121         pub(crate) fn get_fully_signed_copy_holder_tx(&mut self, funding_redeemscript: &Script) -> Transaction {
1122                 let sig = self.signer.unsafe_sign_holder_commitment(&self.holder_commitment, &self.secp_ctx).expect("sign holder commitment");
1123                 self.holder_commitment.add_holder_sig(funding_redeemscript, sig)
1124         }
1125
1126         pub(crate) fn get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
1127                 let get_signed_htlc_tx = |holder_commitment: &HolderCommitmentTransaction| {
1128                         let trusted_tx = holder_commitment.trust();
1129                         if trusted_tx.txid() != outp.txid {
1130                                 return None;
1131                         }
1132                         let (htlc_idx, htlc) = trusted_tx.htlcs().iter().enumerate()
1133                                 .find(|(_, htlc)| htlc.transaction_output_index.unwrap() == outp.vout)
1134                                 .unwrap();
1135                         let counterparty_htlc_sig = holder_commitment.counterparty_htlc_sigs[htlc_idx];
1136                         let mut htlc_tx = trusted_tx.build_unsigned_htlc_tx(
1137                                 &self.channel_transaction_parameters.as_holder_broadcastable(), htlc_idx, preimage,
1138                         );
1139
1140                         let htlc_descriptor = HTLCDescriptor {
1141                                 channel_derivation_parameters: ChannelDerivationParameters {
1142                                         value_satoshis: self.channel_value_satoshis,
1143                                         keys_id: self.channel_keys_id,
1144                                         transaction_parameters: self.channel_transaction_parameters.clone(),
1145                                 },
1146                                 commitment_txid: trusted_tx.txid(),
1147                                 per_commitment_number: trusted_tx.commitment_number(),
1148                                 per_commitment_point: trusted_tx.per_commitment_point(),
1149                                 feerate_per_kw: trusted_tx.feerate_per_kw(),
1150                                 htlc: htlc.clone(),
1151                                 preimage: preimage.clone(),
1152                                 counterparty_sig: counterparty_htlc_sig.clone(),
1153                         };
1154                         let htlc_sig = self.signer.sign_holder_htlc_transaction(&htlc_tx, 0, &htlc_descriptor, &self.secp_ctx).unwrap();
1155                         htlc_tx.input[0].witness = trusted_tx.build_htlc_input_witness(
1156                                 htlc_idx, &counterparty_htlc_sig, &htlc_sig, preimage,
1157                         );
1158                         Some(htlc_tx)
1159                 };
1160
1161                 // Check if the HTLC spends from the current holder commitment first, or the previous.
1162                 get_signed_htlc_tx(&self.holder_commitment)
1163                         .or_else(|| self.prev_holder_commitment.as_ref().and_then(|prev_holder_commitment| get_signed_htlc_tx(prev_holder_commitment)))
1164         }
1165
1166         pub(crate) fn generate_external_htlc_claim(
1167                 &self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>
1168         ) -> Option<ExternalHTLCClaim> {
1169                 let find_htlc = |holder_commitment: &HolderCommitmentTransaction| -> Option<ExternalHTLCClaim> {
1170                         let trusted_tx = holder_commitment.trust();
1171                         if outp.txid != trusted_tx.txid() {
1172                                 return None;
1173                         }
1174                         trusted_tx.htlcs().iter().enumerate()
1175                                 .find(|(_, htlc)| if let Some(output_index) = htlc.transaction_output_index {
1176                                         output_index == outp.vout
1177                                 } else {
1178                                         false
1179                                 })
1180                                 .map(|(htlc_idx, htlc)| {
1181                                         let counterparty_htlc_sig = holder_commitment.counterparty_htlc_sigs[htlc_idx];
1182                                         ExternalHTLCClaim {
1183                                                 commitment_txid: trusted_tx.txid(),
1184                                                 per_commitment_number: trusted_tx.commitment_number(),
1185                                                 htlc: htlc.clone(),
1186                                                 preimage: *preimage,
1187                                                 counterparty_sig: counterparty_htlc_sig,
1188                                         }
1189                                 })
1190                 };
1191                 // Check if the HTLC spends from the current holder commitment or the previous one otherwise.
1192                 find_htlc(&self.holder_commitment)
1193                         .or_else(|| self.prev_holder_commitment.as_ref().map(|c| find_htlc(c)).flatten())
1194         }
1195
1196         pub(crate) fn channel_type_features(&self) -> &ChannelTypeFeatures {
1197                 &self.channel_transaction_parameters.channel_type_features
1198         }
1199 }