_ 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::PackedLockTime;
  16 use bitcoin::blockdata::transaction::Transaction;
  17 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
  18 use bitcoin::blockdata::script::Script;
  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::{ChannelSigner, EntropySource, SignerProvider};
  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::sign::WriteableEcdsaChannelSigner;
  34 use crate::chain::package::{PackageSolvingData, PackageTemplate};
  35 use crate::util::logger::Logger;
  36 use crate::util::ser::{Readable, ReadableArgs, MaybeReadable, UpgradableRequired, Writer, Writeable, VecWriter};
  37
  38 use crate::io;
  39 use crate::prelude::*;
  40 use alloc::collections::BTreeMap;
  41 use core::cmp;
  42 use core::ops::Deref;
  43 use core::mem::replace;
  44 use core::mem::swap;
  45 use crate::ln::features::ChannelTypeFeatures;
  46
  47 const MAX_ALLOC_SIZE: usize = 64*1024;
  48
  49 /// An entry for an [`OnchainEvent`], stating the block height when the event was observed and the
  50 /// transaction causing it.
  51 ///
  52 /// Used to determine when the on-chain event can be considered safe from a chain reorganization.
  53 #[derive(PartialEq, Eq)]
  54 struct OnchainEventEntry {
  55         txid: Txid,
  56         height: u32,
  57         block_hash: Option<BlockHash>, // Added as optional, will be filled in for any entry generated on 0.0.113 or after
  58         event: OnchainEvent,
  59 }
  60
  61 impl OnchainEventEntry {
  62         fn confirmation_threshold(&self) -> u32 {
  63                 self.height + ANTI_REORG_DELAY - 1
  64         }
  65
  66         fn has_reached_confirmation_threshold(&self, height: u32) -> bool {
  67                 height >= self.confirmation_threshold()
  68         }
  69 }
  70
  71 /// Events for claims the [`OnchainTxHandler`] has generated. Once the events are considered safe
  72 /// from a chain reorg, the [`OnchainTxHandler`] will act accordingly.
  73 #[derive(PartialEq, Eq)]
  74 enum OnchainEvent {
  75         /// A pending request has been claimed by a transaction spending the exact same set of outpoints
  76         /// as the request. This claim can either be ours or from the counterparty. Once the claiming
  77         /// transaction has met [`ANTI_REORG_DELAY`] confirmations, we consider it final and remove the
  78         /// pending request.
  79         Claim {
  80                 claim_id: ClaimId,
  81         },
  82         /// The counterparty has claimed an outpoint from one of our pending requests through a
  83         /// different transaction than ours. If our transaction was attempting to claim multiple
  84         /// outputs, we need to drop the outpoint claimed by the counterparty and regenerate a new claim
  85         /// transaction for ourselves. We keep tracking, separately, the outpoint claimed by the
  86         /// counterparty up to [`ANTI_REORG_DELAY`] confirmations to ensure we attempt to re-claim it
  87         /// if the counterparty's claim is reorged from the chain.
  88         ContentiousOutpoint {
  89                 package: PackageTemplate,
  90         }
  91 }
  92
  93 impl Writeable for OnchainEventEntry {
  94         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
  95                 write_tlv_fields!(writer, {
  96                         (0, self.txid, required),
  97                         (1, self.block_hash, option),
  98                         (2, self.height, required),
  99                         (4, self.event, required),
 100                 });
 101                 Ok(())
 102         }
 103 }
 104
 105 impl MaybeReadable for OnchainEventEntry {
 106         fn read<R: io::Read>(reader: &mut R) -> Result<Option<Self>, DecodeError> {
 107                 let mut txid = Txid::all_zeros();
 108                 let mut height = 0;
 109                 let mut block_hash = None;
 110                 let mut event = UpgradableRequired(None);
 111                 read_tlv_fields!(reader, {
 112                         (0, txid, required),
 113                         (1, block_hash, option),
 114                         (2, height, required),
 115                         (4, event, upgradable_required),
 116                 });
 117                 Ok(Some(Self { txid, height, block_hash, event: _init_tlv_based_struct_field!(event, upgradable_required) }))
 118         }
 119 }
 120
 121 impl_writeable_tlv_based_enum_upgradable!(OnchainEvent,
 122         (0, Claim) => {
 123                 (0, claim_id, required),
 124         },
 125         (1, ContentiousOutpoint) => {
 126                 (0, package, required),
 127         },
 128 );
 129
 130 impl Readable for Option<Vec<Option<(usize, Signature)>>> {
 131         fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
 132                 match Readable::read(reader)? {
 133                         0u8 => Ok(None),
 134                         1u8 => {
 135                                 let vlen: u64 = Readable::read(reader)?;
 136                                 let mut ret = Vec::with_capacity(cmp::min(vlen as usize, MAX_ALLOC_SIZE / ::core::mem::size_of::<Option<(usize, Signature)>>()));
 137                                 for _ in 0..vlen {
 138                                         ret.push(match Readable::read(reader)? {
 139                                                 0u8 => None,
 140                                                 1u8 => Some((<u64 as Readable>::read(reader)? as usize, Readable::read(reader)?)),
 141                                                 _ => return Err(DecodeError::InvalidValue)
 142                                         });
 143                                 }
 144                                 Ok(Some(ret))
 145                         },
 146                         _ => Err(DecodeError::InvalidValue),
 147                 }
 148         }
 149 }
 150
 151 impl Writeable for Option<Vec<Option<(usize, Signature)>>> {
 152         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 153                 match self {
 154                         &Some(ref vec) => {
 155                                 1u8.write(writer)?;
 156                                 (vec.len() as u64).write(writer)?;
 157                                 for opt in vec.iter() {
 158                                         match opt {
 159                                                 &Some((ref idx, ref sig)) => {
 160                                                         1u8.write(writer)?;
 161                                                         (*idx as u64).write(writer)?;
 162                                                         sig.write(writer)?;
 163                                                 },
 164                                                 &None => 0u8.write(writer)?,
 165                                         }
 166                                 }
 167                         },
 168                         &None => 0u8.write(writer)?,
 169                 }
 170                 Ok(())
 171         }
 172 }
 173
 174 /// The claim commonly referred to as the pre-signed second-stage HTLC transaction.
 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 pub(crate) enum ClaimEvent {
 186         /// Event yielded to signal that the commitment transaction fee must be bumped to claim any
 187         /// encumbered funds and proceed to HTLC resolution, if any HTLCs exist.
 188         BumpCommitment {
 189                 package_target_feerate_sat_per_1000_weight: u32,
 190                 commitment_tx: Transaction,
 191                 anchor_output_idx: u32,
 192         },
 193         /// Event yielded to signal that the commitment transaction has confirmed and its HTLCs must be
 194         /// resolved by broadcasting a transaction with sufficient fee to claim them.
 195         BumpHTLC {
 196                 target_feerate_sat_per_1000_weight: u32,
 197                 htlcs: Vec<ExternalHTLCClaim>,
 198                 tx_lock_time: PackedLockTime,
 199         },
 200 }
 201
 202 /// Represents the different ways an output can be claimed (i.e., spent to an address under our
 203 /// control) onchain.
 204 pub(crate) enum OnchainClaim {
 205         /// A finalized transaction pending confirmation spending the output to claim.
 206         Tx(Transaction),
 207         /// An event yielded externally to signal additional inputs must be added to a transaction
 208         /// pending confirmation spending the output to claim.
 209         Event(ClaimEvent),
 210 }
 211
 212 /// OnchainTxHandler receives claiming requests, aggregates them if it's sound, broadcast and
 213 /// do RBF bumping if possible.
 214 pub struct OnchainTxHandler<ChannelSigner: WriteableEcdsaChannelSigner> {
 215         destination_script: Script,
 216         holder_commitment: HolderCommitmentTransaction,
 217         // holder_htlc_sigs and prev_holder_htlc_sigs are in the order as they appear in the commitment
 218         // transaction outputs (hence the Option<>s inside the Vec). The first usize is the index in
 219         // the set of HTLCs in the HolderCommitmentTransaction.
 220         holder_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
 221         prev_holder_commitment: Option<HolderCommitmentTransaction>,
 222         prev_holder_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
 223
 224         pub(super) signer: ChannelSigner,
 225         pub(crate) channel_transaction_parameters: ChannelTransactionParameters,
 226
 227         // Used to track claiming requests. If claim tx doesn't confirm before height timer expiration we need to bump
 228         // it (RBF or CPFP). If an input has been part of an aggregate tx at first claim try, we need to keep it within
 229         // another bumped aggregate tx to comply with RBF rules. We may have multiple claiming txn in the flight for the
 230         // same set of outpoints. One of the outpoints may be spent by a transaction not issued by us. That's why at
 231         // block connection we scan all inputs and if any of them is among a set of a claiming request we test for set
 232         // equality between spending transaction and claim request. If true, it means transaction was one our claiming one
 233         // after a security delay of 6 blocks we remove pending claim request. If false, it means transaction wasn't and
 234         // we need to regenerate new claim request with reduced set of still-claimable outpoints.
 235         // Key is identifier of the pending claim request, i.e the txid of the initial claiming transaction generated by
 236         // us and is immutable until all outpoint of the claimable set are post-anti-reorg-delay solved.
 237         // Entry is cache of elements need to generate a bumped claiming transaction (see ClaimTxBumpMaterial)
 238         #[cfg(test)] // Used in functional_test to verify sanitization
 239         pub(crate) pending_claim_requests: HashMap<ClaimId, PackageTemplate>,
 240         #[cfg(not(test))]
 241         pending_claim_requests: HashMap<ClaimId, PackageTemplate>,
 242
 243         // Used to track external events that need to be forwarded to the `ChainMonitor`. This `Vec`
 244         // essentially acts as an insertion-ordered `HashMap` – there should only ever be one occurrence
 245         // of a `ClaimId`, which tracks its latest `ClaimEvent`, i.e., if a pending claim exists, and
 246         // a new block has been connected, resulting in a new claim, the previous will be replaced with
 247         // the new.
 248         //
 249         // These external events may be generated in the following cases:
 250         //      - A channel has been force closed by broadcasting the holder's latest commitment transaction
 251         //      - A block being connected/disconnected
 252         //      - Learning the preimage for an HTLC we can claim onchain
 253         pending_claim_events: Vec<(ClaimId, ClaimEvent)>,
 254
 255         // Used to link outpoints claimed in a connected block to a pending claim request. The keys
 256         // represent the outpoints that our `ChannelMonitor` has detected we have keys/scripts to
 257         // claim. The values track the pending claim request identifier and the initial confirmation
 258         // block height, and are immutable until the outpoint has enough confirmations to meet our
 259         // [`ANTI_REORG_DELAY`]. The initial confirmation block height is used to remove the entry if
 260         // the block gets disconnected.
 261         #[cfg(test)] // Used in functional_test to verify sanitization
 262         pub claimable_outpoints: HashMap<BitcoinOutPoint, (ClaimId, u32)>,
 263         #[cfg(not(test))]
 264         claimable_outpoints: HashMap<BitcoinOutPoint, (ClaimId, u32)>,
 265
 266         locktimed_packages: BTreeMap<u32, Vec<PackageTemplate>>,
 267
 268         onchain_events_awaiting_threshold_conf: Vec<OnchainEventEntry>,
 269
 270         pub(super) secp_ctx: Secp256k1<secp256k1::All>,
 271 }
 272
 273 impl<ChannelSigner: WriteableEcdsaChannelSigner> PartialEq for OnchainTxHandler<ChannelSigner> {
 274         fn eq(&self, other: &Self) -> bool {
 275                 // `signer`, `secp_ctx`, and `pending_claim_events` are excluded on purpose.
 276                 self.destination_script == other.destination_script &&
 277                         self.holder_commitment == other.holder_commitment &&
 278                         self.holder_htlc_sigs == other.holder_htlc_sigs &&
 279                         self.prev_holder_commitment == other.prev_holder_commitment &&
 280                         self.prev_holder_htlc_sigs == other.prev_holder_htlc_sigs &&
 281                         self.channel_transaction_parameters == other.channel_transaction_parameters &&
 282                         self.pending_claim_requests == other.pending_claim_requests &&
 283                         self.claimable_outpoints == other.claimable_outpoints &&
 284                         self.locktimed_packages == other.locktimed_packages &&
 285                         self.onchain_events_awaiting_threshold_conf == other.onchain_events_awaiting_threshold_conf
 286         }
 287 }
 288
 289 const SERIALIZATION_VERSION: u8 = 1;
 290 const MIN_SERIALIZATION_VERSION: u8 = 1;
 291
 292 impl<ChannelSigner: WriteableEcdsaChannelSigner> OnchainTxHandler<ChannelSigner> {
 293         pub(crate) fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 294                 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
 295
 296                 self.destination_script.write(writer)?;
 297                 self.holder_commitment.write(writer)?;
 298                 self.holder_htlc_sigs.write(writer)?;
 299                 self.prev_holder_commitment.write(writer)?;
 300                 self.prev_holder_htlc_sigs.write(writer)?;
 301
 302                 self.channel_transaction_parameters.write(writer)?;
 303
 304                 let mut key_data = VecWriter(Vec::new());
 305                 self.signer.write(&mut key_data)?;
 306                 assert!(key_data.0.len() < core::usize::MAX);
 307                 assert!(key_data.0.len() < core::u32::MAX as usize);
 308                 (key_data.0.len() as u32).write(writer)?;
 309                 writer.write_all(&key_data.0[..])?;
 310
 311                 writer.write_all(&(self.pending_claim_requests.len() as u64).to_be_bytes())?;
 312                 for (ref ancestor_claim_txid, request) in self.pending_claim_requests.iter() {
 313                         ancestor_claim_txid.write(writer)?;
 314                         request.write(writer)?;
 315                 }
 316
 317                 writer.write_all(&(self.claimable_outpoints.len() as u64).to_be_bytes())?;
 318                 for (ref outp, ref claim_and_height) in self.claimable_outpoints.iter() {
 319                         outp.write(writer)?;
 320                         claim_and_height.0.write(writer)?;
 321                         claim_and_height.1.write(writer)?;
 322                 }
 323
 324                 writer.write_all(&(self.locktimed_packages.len() as u64).to_be_bytes())?;
 325                 for (ref locktime, ref packages) in self.locktimed_packages.iter() {
 326                         locktime.write(writer)?;
 327                         writer.write_all(&(packages.len() as u64).to_be_bytes())?;
 328                         for ref package in packages.iter() {
 329                                 package.write(writer)?;
 330                         }
 331                 }
 332
 333                 writer.write_all(&(self.onchain_events_awaiting_threshold_conf.len() as u64).to_be_bytes())?;
 334                 for ref entry in self.onchain_events_awaiting_threshold_conf.iter() {
 335                         entry.write(writer)?;
 336                 }
 337
 338                 write_tlv_fields!(writer, {});
 339                 Ok(())
 340         }
 341 }
 342
 343 impl<'a, 'b, ES: EntropySource, SP: SignerProvider> ReadableArgs<(&'a ES, &'b SP, u64, [u8; 32])> for OnchainTxHandler<SP::Signer> {
 344         fn read<R: io::Read>(reader: &mut R, args: (&'a ES, &'b SP, u64, [u8; 32])) -> Result<Self, DecodeError> {
 345                 let entropy_source = args.0;
 346                 let signer_provider = args.1;
 347                 let channel_value_satoshis = args.2;
 348                 let channel_keys_id = args.3;
 349
 350                 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
 351
 352                 let destination_script = Readable::read(reader)?;
 353
 354                 let holder_commitment = Readable::read(reader)?;
 355                 let holder_htlc_sigs = Readable::read(reader)?;
 356                 let prev_holder_commitment = Readable::read(reader)?;
 357                 let prev_holder_htlc_sigs = Readable::read(reader)?;
 358
 359                 let channel_parameters = Readable::read(reader)?;
 360
 361                 // Read the serialized signer bytes, but don't deserialize them, as we'll obtain our signer
 362                 // by re-deriving the private key material.
 363                 let keys_len: u32 = Readable::read(reader)?;
 364                 let mut bytes_read = 0;
 365                 while bytes_read != keys_len as usize {
 366                         // Read 1KB at a time to avoid accidentally allocating 4GB on corrupted channel keys
 367                         let mut data = [0; 1024];
 368                         let bytes_to_read = cmp::min(1024, keys_len as usize - bytes_read);
 369                         let read_slice = &mut data[0..bytes_to_read];
 370                         reader.read_exact(read_slice)?;
 371                         bytes_read += bytes_to_read;
 372                 }
 373
 374                 let mut signer = signer_provider.derive_channel_signer(channel_value_satoshis, channel_keys_id);
 375                 signer.provide_channel_parameters(&channel_parameters);
 376
 377                 let pending_claim_requests_len: u64 = Readable::read(reader)?;
 378                 let mut pending_claim_requests = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
 379                 for _ in 0..pending_claim_requests_len {
 380                         pending_claim_requests.insert(Readable::read(reader)?, Readable::read(reader)?);
 381                 }
 382
 383                 let claimable_outpoints_len: u64 = Readable::read(reader)?;
 384                 let mut claimable_outpoints = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
 385                 for _ in 0..claimable_outpoints_len {
 386                         let outpoint = Readable::read(reader)?;
 387                         let ancestor_claim_txid = Readable::read(reader)?;
 388                         let height = Readable::read(reader)?;
 389                         claimable_outpoints.insert(outpoint, (ancestor_claim_txid, height));
 390                 }
 391
 392                 let locktimed_packages_len: u64 = Readable::read(reader)?;
 393                 let mut locktimed_packages = BTreeMap::new();
 394                 for _ in 0..locktimed_packages_len {
 395                         let locktime = Readable::read(reader)?;
 396                         let packages_len: u64 = Readable::read(reader)?;
 397                         let mut packages = Vec::with_capacity(cmp::min(packages_len as usize, MAX_ALLOC_SIZE / core::mem::size_of::<PackageTemplate>()));
 398                         for _ in 0..packages_len {
 399                                 packages.push(Readable::read(reader)?);
 400                         }
 401                         locktimed_packages.insert(locktime, packages);
 402                 }
 403
 404                 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
 405                 let mut onchain_events_awaiting_threshold_conf = Vec::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
 406                 for _ in 0..waiting_threshold_conf_len {
 407                         if let Some(val) = MaybeReadable::read(reader)? {
 408                                 onchain_events_awaiting_threshold_conf.push(val);
 409                         }
 410                 }
 411
 412                 read_tlv_fields!(reader, {});
 413
 414                 let mut secp_ctx = Secp256k1::new();
 415                 secp_ctx.seeded_randomize(&entropy_source.get_secure_random_bytes());
 416
 417                 Ok(OnchainTxHandler {
 418                         destination_script,
 419                         holder_commitment,
 420                         holder_htlc_sigs,
 421                         prev_holder_commitment,
 422                         prev_holder_htlc_sigs,
 423                         signer,
 424                         channel_transaction_parameters: channel_parameters,
 425                         claimable_outpoints,
 426                         locktimed_packages,
 427                         pending_claim_requests,
 428                         onchain_events_awaiting_threshold_conf,
 429                         pending_claim_events: Vec::new(),
 430                         secp_ctx,
 431                 })
 432         }
 433 }
 434
 435 impl<ChannelSigner: WriteableEcdsaChannelSigner> OnchainTxHandler<ChannelSigner> {
 436         pub(crate) fn new(destination_script: Script, signer: ChannelSigner, channel_parameters: ChannelTransactionParameters, holder_commitment: HolderCommitmentTransaction, secp_ctx: Secp256k1<secp256k1::All>) -> Self {
 437                 OnchainTxHandler {
 438                         destination_script,
 439                         holder_commitment,
 440                         holder_htlc_sigs: None,
 441                         prev_holder_commitment: None,
 442                         prev_holder_htlc_sigs: None,
 443                         signer,
 444                         channel_transaction_parameters: channel_parameters,
 445                         pending_claim_requests: HashMap::new(),
 446                         claimable_outpoints: HashMap::new(),
 447                         locktimed_packages: BTreeMap::new(),
 448                         onchain_events_awaiting_threshold_conf: Vec::new(),
 449                         pending_claim_events: Vec::new(),
 450                         secp_ctx,
 451                 }
 452         }
 453
 454         pub(crate) fn get_prev_holder_commitment_to_self_value(&self) -> Option<u64> {
 455                 self.prev_holder_commitment.as_ref().map(|commitment| commitment.to_broadcaster_value_sat())
 456         }
 457
 458         pub(crate) fn get_cur_holder_commitment_to_self_value(&self) -> u64 {
 459                 self.holder_commitment.to_broadcaster_value_sat()
 460         }
 461
 462         pub(crate) fn get_and_clear_pending_claim_events(&mut self) -> Vec<(ClaimId, ClaimEvent)> {
 463                 let mut events = Vec::new();
 464                 swap(&mut events, &mut self.pending_claim_events);
 465                 events
 466         }
 467
 468         /// Triggers rebroadcasts/fee-bumps of pending claims from a force-closed channel. This is
 469         /// crucial in preventing certain classes of pinning attacks, detecting substantial mempool
 470         /// feerate changes between blocks, and ensuring reliability if broadcasting fails. We recommend
 471         /// invoking this every 30 seconds, or lower if running in an environment with spotty
 472         /// connections, like on mobile.
 473         pub(crate) fn rebroadcast_pending_claims<B: Deref, F: Deref, L: Deref>(
 474                 &mut self, current_height: u32, broadcaster: &B, fee_estimator: &LowerBoundedFeeEstimator<F>,
 475                 logger: &L,
 476         )
 477         where
 478                 B::Target: BroadcasterInterface,
 479                 F::Target: FeeEstimator,
 480                 L::Target: Logger,
 481         {
 482                 let mut bump_requests = Vec::with_capacity(self.pending_claim_requests.len());
 483                 for (claim_id, request) in self.pending_claim_requests.iter() {
 484                         let inputs = request.outpoints();
 485                         log_info!(logger, "Triggering rebroadcast/fee-bump for request with inputs {:?}", inputs);
 486                         bump_requests.push((*claim_id, request.clone()));
 487                 }
 488                 for (claim_id, request) in bump_requests {
 489                         self.generate_claim(current_height, &request, false /* force_feerate_bump */, fee_estimator, logger)
 490                                 .map(|(_, new_feerate, claim)| {
 491                                         let mut bumped_feerate = false;
 492                                         if let Some(mut_request) = self.pending_claim_requests.get_mut(&claim_id) {
 493                                                 bumped_feerate = request.previous_feerate() > new_feerate;
 494                                                 mut_request.set_feerate(new_feerate);
 495                                         }
 496                                         match claim {
 497                                                 OnchainClaim::Tx(tx) => {
 498                                                         let log_start = if bumped_feerate { "Broadcasting RBF-bumped" } else { "Rebroadcasting" };
 499                                                         log_info!(logger, "{} onchain {}", log_start, log_tx!(tx));
 500                                                         broadcaster.broadcast_transactions(&[&tx]);
 501                                                 },
 502                                                 OnchainClaim::Event(event) => {
 503                                                         let log_start = if bumped_feerate { "Yielding fee-bumped" } else { "Replaying" };
 504                                                         log_info!(logger, "{} onchain event to spend inputs {:?}", log_start,
 505                                                                 request.outpoints());
 506                                                         #[cfg(debug_assertions)] {
 507                                                                 debug_assert!(request.requires_external_funding());
 508                                                                 let num_existing = self.pending_claim_events.iter()
 509                                                                         .filter(|entry| entry.0 == claim_id).count();
 510                                                                 assert!(num_existing == 0 || num_existing == 1);
 511                                                         }
 512                                                         self.pending_claim_events.retain(|event| event.0 != claim_id);
 513                                                         self.pending_claim_events.push((claim_id, event));
 514                                                 }
 515                                         }
 516                                 });
 517                 }
 518         }
 519
 520         /// Lightning security model (i.e being able to redeem/timeout HTLC or penalize counterparty
 521         /// onchain) lays on the assumption of claim transactions getting confirmed before timelock
 522         /// expiration (CSV or CLTV following cases). In case of high-fee spikes, claim tx may get stuck
 523         /// in the mempool, so you need to bump its feerate quickly using Replace-By-Fee or
 524         /// Child-Pay-For-Parent.
 525         ///
 526         /// Panics if there are signing errors, because signing operations in reaction to on-chain
 527         /// events are not expected to fail, and if they do, we may lose funds.
 528         fn generate_claim<F: Deref, L: Deref>(
 529                 &mut self, cur_height: u32, cached_request: &PackageTemplate, force_feerate_bump: bool,
 530                 fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L,
 531         ) -> Option<(u32, u64, OnchainClaim)>
 532         where
 533                 F::Target: FeeEstimator,
 534                 L::Target: Logger,
 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::HighPriority, 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: PackedLockTime(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());
 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::HighPriority;
 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() as u64);
 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         /// Upon channelmonitor.block_connected(..) or upon provision of a preimage on the forward link
 680         /// for this channel, provide new relevant on-chain transactions and/or new claim requests.
 681         /// Together with `update_claims_view_from_matched_txn` this used to be named
 682         /// `block_connected`, but it is now also used for claiming an HTLC output if we receive a
 683         /// preimage after force-close.
 684         ///
 685         /// `conf_height` represents the height at which the request was generated. This
 686         /// does not need to equal the current blockchain tip height, which should be provided via
 687         /// `cur_height`, however it must never be higher than `cur_height`.
 688         pub(crate) fn update_claims_view_from_requests<B: Deref, F: Deref, L: Deref>(
 689                 &mut self, requests: Vec<PackageTemplate>, conf_height: u32, cur_height: u32,
 690                 broadcaster: &B, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L
 691         ) where
 692                 B::Target: BroadcasterInterface,
 693                 F::Target: FeeEstimator,
 694                 L::Target: Logger,
 695         {
 696                 log_debug!(logger, "Updating claims view at height {} with {} claim requests", cur_height, requests.len());
 697                 let mut preprocessed_requests = Vec::with_capacity(requests.len());
 698                 let mut aggregated_request = None;
 699
 700                 // Try to aggregate outputs if their timelock expiration isn't imminent (package timelock
 701                 // <= CLTV_SHARED_CLAIM_BUFFER) and they don't require an immediate nLockTime (aggregable).
 702                 for req in requests {
 703                         // Don't claim a outpoint twice that would be bad for privacy and may uselessly lock a CPFP input for a while
 704                         if let Some(_) = self.claimable_outpoints.get(req.outpoints()[0]) {
 705                                 log_info!(logger, "Ignoring second claim for outpoint {}:{}, already registered its claiming request", req.outpoints()[0].txid, req.outpoints()[0].vout);
 706                         } else {
 707                                 let timelocked_equivalent_package = self.locktimed_packages.iter().map(|v| v.1.iter()).flatten()
 708                                         .find(|locked_package| locked_package.outpoints() == req.outpoints());
 709                                 if let Some(package) = timelocked_equivalent_package {
 710                                         log_info!(logger, "Ignoring second claim for outpoint {}:{}, we already have one which we're waiting on a timelock at {} for.",
 711                                                 req.outpoints()[0].txid, req.outpoints()[0].vout, package.package_locktime(cur_height));
 712                                         continue;
 713                                 }
 714
 715                                 let package_locktime = req.package_locktime(cur_height);
 716                                 if package_locktime > cur_height + 1 {
 717                                         log_info!(logger, "Delaying claim of package until its timelock at {} (current height {}), the following outpoints are spent:", package_locktime, cur_height);
 718                                         for outpoint in req.outpoints() {
 719                                                 log_info!(logger, "  Outpoint {}", outpoint);
 720                                         }
 721                                         self.locktimed_packages.entry(package_locktime).or_insert(Vec::new()).push(req);
 722                                         continue;
 723                                 }
 724
 725                                 log_trace!(logger, "Test if outpoint can be aggregated with expiration {} against {}", req.timelock(), cur_height + CLTV_SHARED_CLAIM_BUFFER);
 726                                 if req.timelock() <= cur_height + CLTV_SHARED_CLAIM_BUFFER || !req.aggregable() {
 727                                         // Don't aggregate if outpoint package timelock is soon or marked as non-aggregable
 728                                         preprocessed_requests.push(req);
 729                                 } else if aggregated_request.is_none() {
 730                                         aggregated_request = Some(req);
 731                                 } else {
 732                                         aggregated_request.as_mut().unwrap().merge_package(req);
 733                                 }
 734                         }
 735                 }
 736                 if let Some(req) = aggregated_request {
 737                         preprocessed_requests.push(req);
 738                 }
 739
 740                 // Claim everything up to and including `cur_height`
 741                 let remaining_locked_packages = self.locktimed_packages.split_off(&(cur_height + 1));
 742                 for (pop_height, mut entry) in self.locktimed_packages.iter_mut() {
 743                         log_trace!(logger, "Restoring delayed claim of package(s) at their timelock at {}.", pop_height);
 744                         preprocessed_requests.append(&mut entry);
 745                 }
 746                 self.locktimed_packages = remaining_locked_packages;
 747
 748                 // Generate claim transactions and track them to bump if necessary at
 749                 // height timer expiration (i.e in how many blocks we're going to take action).
 750                 for mut req in preprocessed_requests {
 751                         if let Some((new_timer, new_feerate, claim)) = self.generate_claim(
 752                                 cur_height, &req, true /* force_feerate_bump */, &*fee_estimator, &*logger,
 753                         ) {
 754                                 req.set_timer(new_timer);
 755                                 req.set_feerate(new_feerate);
 756                                 // Once a pending claim has an id assigned, it remains fixed until the claim is
 757                                 // satisfied, regardless of whether the claim switches between different variants of
 758                                 // `OnchainClaim`.
 759                                 let claim_id = match claim {
 760                                         OnchainClaim::Tx(tx) => {
 761                                                 log_info!(logger, "Broadcasting onchain {}", log_tx!(tx));
 762                                                 broadcaster.broadcast_transactions(&[&tx]);
 763                                                 ClaimId(tx.txid().into_inner())
 764                                         },
 765                                         OnchainClaim::Event(claim_event) => {
 766                                                 log_info!(logger, "Yielding onchain event to spend inputs {:?}", req.outpoints());
 767                                                 let claim_id = match claim_event {
 768                                                         ClaimEvent::BumpCommitment { ref commitment_tx, .. } =>
 769                                                                 // For commitment claims, we can just use their txid as it should
 770                                                                 // already be unique.
 771                                                                 ClaimId(commitment_tx.txid().into_inner()),
 772                                                         ClaimEvent::BumpHTLC { ref htlcs, .. } => {
 773                                                                 // For HTLC claims, commit to the entire set of HTLC outputs to
 774                                                                 // claim, which will always be unique per request. Once a claim ID
 775                                                                 // is generated, it is assigned and remains unchanged, even if the
 776                                                                 // underlying set of HTLCs changes.
 777                                                                 let mut engine = Sha256::engine();
 778                                                                 for htlc in htlcs {
 779                                                                         engine.input(&htlc.commitment_txid.into_inner());
 780                                                                         engine.input(&htlc.htlc.transaction_output_index.unwrap().to_be_bytes());
 781                                                                 }
 782                                                                 ClaimId(Sha256::from_engine(engine).into_inner())
 783                                                         },
 784                                                 };
 785                                                 debug_assert!(self.pending_claim_requests.get(&claim_id).is_none());
 786                                                 debug_assert_eq!(self.pending_claim_events.iter().filter(|entry| entry.0 == claim_id).count(), 0);
 787                                                 self.pending_claim_events.push((claim_id, claim_event));
 788                                                 claim_id
 789                                         },
 790                                 };
 791                                 debug_assert!(self.pending_claim_requests.get(&claim_id).is_none());
 792                                 for k in req.outpoints() {
 793                                         log_info!(logger, "Registering claiming request for {}:{}", k.txid, k.vout);
 794                                         self.claimable_outpoints.insert(k.clone(), (claim_id, conf_height));
 795                                 }
 796                                 self.pending_claim_requests.insert(claim_id, req);
 797                         }
 798                 }
 799         }
 800
 801         /// Upon channelmonitor.block_connected(..) or upon provision of a preimage on the forward link
 802         /// for this channel, provide new relevant on-chain transactions and/or new claim requests.
 803         /// Together with `update_claims_view_from_requests` this used to be named `block_connected`,
 804         /// but it is now also used for claiming an HTLC output if we receive a preimage after force-close.
 805         ///
 806         /// `conf_height` represents the height at which the transactions in `txn_matched` were
 807         /// confirmed. This does not need to equal the current blockchain tip height, which should be
 808         /// provided via `cur_height`, however it must never be higher than `cur_height`.
 809         pub(crate) fn update_claims_view_from_matched_txn<B: Deref, F: Deref, L: Deref>(
 810                 &mut self, txn_matched: &[&Transaction], conf_height: u32, conf_hash: BlockHash,
 811                 cur_height: u32, broadcaster: &B, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L
 812         ) where
 813                 B::Target: BroadcasterInterface,
 814                 F::Target: FeeEstimator,
 815                 L::Target: Logger,
 816         {
 817                 log_debug!(logger, "Updating claims view at height {} with {} matched transactions in block {}", cur_height, txn_matched.len(), conf_height);
 818                 let mut bump_candidates = HashMap::new();
 819                 for tx in txn_matched {
 820                         // Scan all input to verify is one of the outpoint spent is of interest for us
 821                         let mut claimed_outputs_material = Vec::new();
 822                         for inp in &tx.input {
 823                                 if let Some((claim_id, _)) = self.claimable_outpoints.get(&inp.previous_output) {
 824                                         // If outpoint has claim request pending on it...
 825                                         if let Some(request) = self.pending_claim_requests.get_mut(claim_id) {
 826                                                 //... we need to verify equality between transaction outpoints and claim request
 827                                                 // outpoints to know if transaction is the original claim or a bumped one issued
 828                                                 // by us.
 829                                                 let mut are_sets_equal = true;
 830                                                 let mut tx_inputs = tx.input.iter().map(|input| &input.previous_output).collect::<Vec<_>>();
 831                                                 tx_inputs.sort_unstable();
 832                                                 for request_input in request.outpoints() {
 833                                                         if tx_inputs.binary_search(&request_input).is_err() {
 834                                                                 are_sets_equal = false;
 835                                                                 break;
 836                                                         }
 837                                                 }
 838
 839                                                 macro_rules! clean_claim_request_after_safety_delay {
 840                                                         () => {
 841                                                                 let entry = OnchainEventEntry {
 842                                                                         txid: tx.txid(),
 843                                                                         height: conf_height,
 844                                                                         block_hash: Some(conf_hash),
 845                                                                         event: OnchainEvent::Claim { claim_id: *claim_id }
 846                                                                 };
 847                                                                 if !self.onchain_events_awaiting_threshold_conf.contains(&entry) {
 848                                                                         self.onchain_events_awaiting_threshold_conf.push(entry);
 849                                                                 }
 850                                                         }
 851                                                 }
 852
 853                                                 // If this is our transaction (or our counterparty spent all the outputs
 854                                                 // before we could anyway with same inputs order than us), wait for
 855                                                 // ANTI_REORG_DELAY and clean the RBF tracking map.
 856                                                 if are_sets_equal {
 857                                                         clean_claim_request_after_safety_delay!();
 858                                                 } else { // If false, generate new claim request with update outpoint set
 859                                                         let mut at_least_one_drop = false;
 860                                                         for input in tx.input.iter() {
 861                                                                 if let Some(package) = request.split_package(&input.previous_output) {
 862                                                                         claimed_outputs_material.push(package);
 863                                                                         at_least_one_drop = true;
 864                                                                 }
 865                                                                 // If there are no outpoints left to claim in this request, drop it entirely after ANTI_REORG_DELAY.
 866                                                                 if request.outpoints().is_empty() {
 867                                                                         clean_claim_request_after_safety_delay!();
 868                                                                 }
 869                                                         }
 870                                                         //TODO: recompute soonest_timelock to avoid wasting a bit on fees
 871                                                         if at_least_one_drop {
 872                                                                 bump_candidates.insert(*claim_id, request.clone());
 873                                                                 // If we have any pending claim events for the request being updated
 874                                                                 // that have yet to be consumed, we'll remove them since they will
 875                                                                 // end up producing an invalid transaction by double spending
 876                                                                 // input(s) that already have a confirmed spend. If such spend is
 877                                                                 // reorged out of the chain, then we'll attempt to re-spend the
 878                                                                 // inputs once we see it.
 879                                                                 #[cfg(debug_assertions)] {
 880                                                                         let existing = self.pending_claim_events.iter()
 881                                                                                 .filter(|entry| entry.0 == *claim_id).count();
 882                                                                         assert!(existing == 0 || existing == 1);
 883                                                                 }
 884                                                                 self.pending_claim_events.retain(|entry| entry.0 != *claim_id);
 885                                                         }
 886                                                 }
 887                                                 break; //No need to iterate further, either tx is our or their
 888                                         } else {
 889                                                 panic!("Inconsistencies between pending_claim_requests map and claimable_outpoints map");
 890                                         }
 891                                 }
 892                         }
 893                         for package in claimed_outputs_material.drain(..) {
 894                                 let entry = OnchainEventEntry {
 895                                         txid: tx.txid(),
 896                                         height: conf_height,
 897                                         block_hash: Some(conf_hash),
 898                                         event: OnchainEvent::ContentiousOutpoint { package },
 899                                 };
 900                                 if !self.onchain_events_awaiting_threshold_conf.contains(&entry) {
 901                                         self.onchain_events_awaiting_threshold_conf.push(entry);
 902                                 }
 903                         }
 904                 }
 905
 906                 // After security delay, either our claim tx got enough confs or outpoint is definetely out of reach
 907                 let onchain_events_awaiting_threshold_conf =
 908                         self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
 909                 for entry in onchain_events_awaiting_threshold_conf {
 910                         if entry.has_reached_confirmation_threshold(cur_height) {
 911                                 match entry.event {
 912                                         OnchainEvent::Claim { claim_id } => {
 913                                                 // We may remove a whole set of claim outpoints here, as these one may have
 914                                                 // been aggregated in a single tx and claimed so atomically
 915                                                 if let Some(request) = self.pending_claim_requests.remove(&claim_id) {
 916                                                         for outpoint in request.outpoints() {
 917                                                                 log_debug!(logger, "Removing claim tracking for {} due to maturation of claim package {}.",
 918                                                                         outpoint, log_bytes!(claim_id.0));
 919                                                                 self.claimable_outpoints.remove(outpoint);
 920                                                         }
 921                                                         #[cfg(debug_assertions)] {
 922                                                                 let num_existing = self.pending_claim_events.iter()
 923                                                                         .filter(|entry| entry.0 == claim_id).count();
 924                                                                 assert!(num_existing == 0 || num_existing == 1);
 925                                                         }
 926                                                         self.pending_claim_events.retain(|(id, _)| *id != claim_id);
 927                                                 }
 928                                         },
 929                                         OnchainEvent::ContentiousOutpoint { package } => {
 930                                                 log_debug!(logger, "Removing claim tracking due to maturation of claim tx for outpoints:");
 931                                                 log_debug!(logger, " {:?}", package.outpoints());
 932                                                 self.claimable_outpoints.remove(package.outpoints()[0]);
 933                                         }
 934                                 }
 935                         } else {
 936                                 self.onchain_events_awaiting_threshold_conf.push(entry);
 937                         }
 938                 }
 939
 940                 // Check if any pending claim request must be rescheduled
 941                 for (claim_id, request) in self.pending_claim_requests.iter() {
 942                         if cur_height >= request.timer() {
 943                                 bump_candidates.insert(*claim_id, request.clone());
 944                         }
 945                 }
 946
 947                 // Build, bump and rebroadcast tx accordingly
 948                 log_trace!(logger, "Bumping {} candidates", bump_candidates.len());
 949                 for (claim_id, request) in bump_candidates.iter() {
 950                         if let Some((new_timer, new_feerate, bump_claim)) = self.generate_claim(
 951                                 cur_height, &request, true /* force_feerate_bump */, &*fee_estimator, &*logger,
 952                         ) {
 953                                 match bump_claim {
 954                                         OnchainClaim::Tx(bump_tx) => {
 955                                                 log_info!(logger, "Broadcasting RBF-bumped onchain {}", log_tx!(bump_tx));
 956                                                 broadcaster.broadcast_transactions(&[&bump_tx]);
 957                                         },
 958                                         OnchainClaim::Event(claim_event) => {
 959                                                 log_info!(logger, "Yielding RBF-bumped onchain event to spend inputs {:?}", request.outpoints());
 960                                                 #[cfg(debug_assertions)] {
 961                                                         let num_existing = self.pending_claim_events.iter().
 962                                                                 filter(|entry| entry.0 == *claim_id).count();
 963                                                         assert!(num_existing == 0 || num_existing == 1);
 964                                                 }
 965                                                 self.pending_claim_events.retain(|event| event.0 != *claim_id);
 966                                                 self.pending_claim_events.push((*claim_id, claim_event));
 967                                         },
 968                                 }
 969                                 if let Some(request) = self.pending_claim_requests.get_mut(claim_id) {
 970                                         request.set_timer(new_timer);
 971                                         request.set_feerate(new_feerate);
 972                                 }
 973                         }
 974                 }
 975         }
 976
 977         pub(crate) fn transaction_unconfirmed<B: Deref, F: Deref, L: Deref>(
 978                 &mut self,
 979                 txid: &Txid,
 980                 broadcaster: B,
 981                 fee_estimator: &LowerBoundedFeeEstimator<F>,
 982                 logger: L,
 983         ) where
 984                 B::Target: BroadcasterInterface,
 985                 F::Target: FeeEstimator,
 986                 L::Target: Logger,
 987         {
 988                 let mut height = None;
 989                 for entry in self.onchain_events_awaiting_threshold_conf.iter() {
 990                         if entry.txid == *txid {
 991                                 height = Some(entry.height);
 992                                 break;
 993                         }
 994                 }
 995
 996                 if let Some(height) = height {
 997                         self.block_disconnected(height, broadcaster, fee_estimator, logger);
 998                 }
 999         }
1000
1001         pub(crate) fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, height: u32, broadcaster: B, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: L)
1002                 where B::Target: BroadcasterInterface,
1003                       F::Target: FeeEstimator,
1004                                         L::Target: Logger,
1005         {
1006                 let mut bump_candidates = HashMap::new();
1007                 let onchain_events_awaiting_threshold_conf =
1008                         self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
1009                 for entry in onchain_events_awaiting_threshold_conf {
1010                         if entry.height >= height {
1011                                 //- our claim tx on a commitment tx output
1012                                 //- resurect outpoint back in its claimable set and regenerate tx
1013                                 match entry.event {
1014                                         OnchainEvent::ContentiousOutpoint { package } => {
1015                                                 if let Some(pending_claim) = self.claimable_outpoints.get(package.outpoints()[0]) {
1016                                                         if let Some(request) = self.pending_claim_requests.get_mut(&pending_claim.0) {
1017                                                                 request.merge_package(package);
1018                                                                 // Using a HashMap guarantee us than if we have multiple outpoints getting
1019                                                                 // resurrected only one bump claim tx is going to be broadcast
1020                                                                 bump_candidates.insert(pending_claim.clone(), request.clone());
1021                                                         }
1022                                                 }
1023                                         },
1024                                         _ => {},
1025                                 }
1026                         } else {
1027                                 self.onchain_events_awaiting_threshold_conf.push(entry);
1028                         }
1029                 }
1030                 for ((_claim_id, _), ref mut request) in bump_candidates.iter_mut() {
1031                         // `height` is the height being disconnected, so our `current_height` is 1 lower.
1032                         let current_height = height - 1;
1033                         if let Some((new_timer, new_feerate, bump_claim)) = self.generate_claim(
1034                                 current_height, &request, true /* force_feerate_bump */, fee_estimator, &&*logger
1035                         ) {
1036                                 request.set_timer(new_timer);
1037                                 request.set_feerate(new_feerate);
1038                                 match bump_claim {
1039                                         OnchainClaim::Tx(bump_tx) => {
1040                                                 log_info!(logger, "Broadcasting onchain {}", log_tx!(bump_tx));
1041                                                 broadcaster.broadcast_transactions(&[&bump_tx]);
1042                                         },
1043                                         OnchainClaim::Event(claim_event) => {
1044                                                 log_info!(logger, "Yielding onchain event after reorg to spend inputs {:?}", request.outpoints());
1045                                                 #[cfg(debug_assertions)] {
1046                                                         let num_existing = self.pending_claim_events.iter()
1047                                                                 .filter(|entry| entry.0 == *_claim_id).count();
1048                                                         assert!(num_existing == 0 || num_existing == 1);
1049                                                 }
1050                                                 self.pending_claim_events.retain(|event| event.0 != *_claim_id);
1051                                                 self.pending_claim_events.push((*_claim_id, claim_event));
1052                                         },
1053                                 }
1054                         }
1055                 }
1056                 for (ancestor_claim_txid, request) in bump_candidates.drain() {
1057                         self.pending_claim_requests.insert(ancestor_claim_txid.0, request);
1058                 }
1059                 //TODO: if we implement cross-block aggregated claim transaction we need to refresh set of outpoints and regenerate tx but
1060                 // right now if one of the outpoint get disconnected, just erase whole pending claim request.
1061                 let mut remove_request = Vec::new();
1062                 self.claimable_outpoints.retain(|_, ref v|
1063                         if v.1 >= height {
1064                         remove_request.push(v.0.clone());
1065                         false
1066                         } else { true });
1067                 for req in remove_request {
1068                         self.pending_claim_requests.remove(&req);
1069                 }
1070         }
1071
1072         pub(crate) fn is_output_spend_pending(&self, outpoint: &BitcoinOutPoint) -> bool {
1073                 self.claimable_outpoints.get(outpoint).is_some()
1074         }
1075
1076         pub(crate) fn get_relevant_txids(&self) -> Vec<(Txid, Option<BlockHash>)> {
1077                 let mut txids: Vec<(Txid, Option<BlockHash>)> = self.onchain_events_awaiting_threshold_conf
1078                         .iter()
1079                         .map(|entry| (entry.txid, entry.block_hash))
1080                         .collect();
1081                 txids.sort_unstable_by_key(|(txid, _)| *txid);
1082                 txids.dedup();
1083                 txids
1084         }
1085
1086         pub(crate) fn provide_latest_holder_tx(&mut self, tx: HolderCommitmentTransaction) {
1087                 self.prev_holder_commitment = Some(replace(&mut self.holder_commitment, tx));
1088                 self.holder_htlc_sigs = None;
1089         }
1090
1091         // Normally holder HTLCs are signed at the same time as the holder commitment tx.  However,
1092         // in some configurations, the holder commitment tx has been signed and broadcast by a
1093         // ChannelMonitor replica, so we handle that case here.
1094         fn sign_latest_holder_htlcs(&mut self) {
1095                 if self.holder_htlc_sigs.is_none() {
1096                         let (_sig, sigs) = self.signer.sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("sign holder commitment");
1097                         self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, sigs));
1098                 }
1099         }
1100
1101         // Normally only the latest commitment tx and HTLCs need to be signed.  However, in some
1102         // configurations we may have updated our holder commitment but a replica of the ChannelMonitor
1103         // broadcast the previous one before we sync with it.  We handle that case here.
1104         fn sign_prev_holder_htlcs(&mut self) {
1105                 if self.prev_holder_htlc_sigs.is_none() {
1106                         if let Some(ref holder_commitment) = self.prev_holder_commitment {
1107                                 let (_sig, sigs) = self.signer.sign_holder_commitment_and_htlcs(holder_commitment, &self.secp_ctx).expect("sign previous holder commitment");
1108                                 self.prev_holder_htlc_sigs = Some(Self::extract_holder_sigs(holder_commitment, sigs));
1109                         }
1110                 }
1111         }
1112
1113         fn extract_holder_sigs(holder_commitment: &HolderCommitmentTransaction, sigs: Vec<Signature>) -> Vec<Option<(usize, Signature)>> {
1114                 let mut ret = Vec::new();
1115                 for (htlc_idx, (holder_sig, htlc)) in sigs.iter().zip(holder_commitment.htlcs().iter()).enumerate() {
1116                         let tx_idx = htlc.transaction_output_index.unwrap();
1117                         if ret.len() <= tx_idx as usize { ret.resize(tx_idx as usize + 1, None); }
1118                         ret[tx_idx as usize] = Some((htlc_idx, holder_sig.clone()));
1119                 }
1120                 ret
1121         }
1122
1123         //TODO: getting lastest holder transactions should be infallible and result in us "force-closing the channel", but we may
1124         // have empty holder commitment transaction if a ChannelMonitor is asked to force-close just after Channel::get_outbound_funding_created,
1125         // before providing a initial commitment transaction. For outbound channel, init ChannelMonitor at Channel::funding_signed, there is nothing
1126         // to monitor before.
1127         pub(crate) fn get_fully_signed_holder_tx(&mut self, funding_redeemscript: &Script) -> Transaction {
1128                 let (sig, htlc_sigs) = self.signer.sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("signing holder commitment");
1129                 self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, htlc_sigs));
1130                 self.holder_commitment.add_holder_sig(funding_redeemscript, sig)
1131         }
1132
1133         #[cfg(any(test, feature="unsafe_revoked_tx_signing"))]
1134         pub(crate) fn get_fully_signed_copy_holder_tx(&mut self, funding_redeemscript: &Script) -> Transaction {
1135                 let (sig, htlc_sigs) = self.signer.unsafe_sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("sign holder commitment");
1136                 self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, htlc_sigs));
1137                 self.holder_commitment.add_holder_sig(funding_redeemscript, sig)
1138         }
1139
1140         pub(crate) fn get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
1141                 let mut htlc_tx = None;
1142                 let commitment_txid = self.holder_commitment.trust().txid();
1143                 // Check if the HTLC spends from the current holder commitment
1144                 if commitment_txid == outp.txid {
1145                         self.sign_latest_holder_htlcs();
1146                         if let &Some(ref htlc_sigs) = &self.holder_htlc_sigs {
1147                                 let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
1148                                 let trusted_tx = self.holder_commitment.trust();
1149                                 let counterparty_htlc_sig = self.holder_commitment.counterparty_htlc_sigs[*htlc_idx];
1150                                 htlc_tx = Some(trusted_tx
1151                                         .get_signed_htlc_tx(&self.channel_transaction_parameters.as_holder_broadcastable(), *htlc_idx, &counterparty_htlc_sig, htlc_sig, preimage));
1152                         }
1153                 }
1154                 // If the HTLC doesn't spend the current holder commitment, check if it spends the previous one
1155                 if htlc_tx.is_none() && self.prev_holder_commitment.is_some() {
1156                         let commitment_txid = self.prev_holder_commitment.as_ref().unwrap().trust().txid();
1157                         if commitment_txid == outp.txid {
1158                                 self.sign_prev_holder_htlcs();
1159                                 if let &Some(ref htlc_sigs) = &self.prev_holder_htlc_sigs {
1160                                         let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
1161                                         let holder_commitment = self.prev_holder_commitment.as_ref().unwrap();
1162                                         let trusted_tx = holder_commitment.trust();
1163                                         let counterparty_htlc_sig = holder_commitment.counterparty_htlc_sigs[*htlc_idx];
1164                                         htlc_tx = Some(trusted_tx
1165                                                 .get_signed_htlc_tx(&self.channel_transaction_parameters.as_holder_broadcastable(), *htlc_idx, &counterparty_htlc_sig, htlc_sig, preimage));
1166                                 }
1167                         }
1168                 }
1169                 htlc_tx
1170         }
1171
1172         pub(crate) fn generate_external_htlc_claim(
1173                 &self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>
1174         ) -> Option<ExternalHTLCClaim> {
1175                 let find_htlc = |holder_commitment: &HolderCommitmentTransaction| -> Option<ExternalHTLCClaim> {
1176                         let trusted_tx = holder_commitment.trust();
1177                         if outp.txid != trusted_tx.txid() {
1178                                 return None;
1179                         }
1180                         trusted_tx.htlcs().iter().enumerate()
1181                                 .find(|(_, htlc)| if let Some(output_index) = htlc.transaction_output_index {
1182                                         output_index == outp.vout
1183                                 } else {
1184                                         false
1185                                 })
1186                                 .map(|(htlc_idx, htlc)| {
1187                                         let counterparty_htlc_sig = holder_commitment.counterparty_htlc_sigs[htlc_idx];
1188                                         ExternalHTLCClaim {
1189                                                 commitment_txid: trusted_tx.txid(),
1190                                                 per_commitment_number: trusted_tx.commitment_number(),
1191                                                 htlc: htlc.clone(),
1192                                                 preimage: *preimage,
1193                                                 counterparty_sig: counterparty_htlc_sig,
1194                                         }
1195                                 })
1196                 };
1197                 // Check if the HTLC spends from the current holder commitment or the previous one otherwise.
1198                 find_htlc(&self.holder_commitment)
1199                         .or_else(|| self.prev_holder_commitment.as_ref().map(|c| find_htlc(c)).flatten())
1200         }
1201
1202         pub(crate) fn channel_type_features(&self) -> &ChannelTypeFeatures {
1203                 &self.channel_transaction_parameters.channel_type_features
1204         }
1205
1206         #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
1207         pub(crate) fn unsafe_get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
1208                 let latest_had_sigs = self.holder_htlc_sigs.is_some();
1209                 let prev_had_sigs = self.prev_holder_htlc_sigs.is_some();
1210                 let ret = self.get_fully_signed_htlc_tx(outp, preimage);
1211                 if !latest_had_sigs {
1212                         self.holder_htlc_sigs = None;
1213                 }
1214                 if !prev_had_sigs {
1215                         self.prev_holder_htlc_sigs = None;
1216                 }
1217                 ret
1218         }
1219 }