_ 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::transaction::Transaction;
  16 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
  17 use bitcoin::blockdata::script::Script;
  18
  19 use bitcoin::hash_types::Txid;
  20
  21 use bitcoin::secp256k1::{Secp256k1, ecdsa::Signature};
  22 use bitcoin::secp256k1;
  23
  24 use ln::msgs::DecodeError;
  25 use ln::PaymentPreimage;
  26 use ln::chan_utils::{ChannelTransactionParameters, HolderCommitmentTransaction};
  27 use chain::chaininterface::{FeeEstimator, BroadcasterInterface, LowerBoundedFeeEstimator};
  28 use chain::channelmonitor::{ANTI_REORG_DELAY, CLTV_SHARED_CLAIM_BUFFER};
  29 use chain::keysinterface::{Sign, KeysInterface};
  30 use chain::package::PackageTemplate;
  31 use util::logger::Logger;
  32 use util::ser::{Readable, ReadableArgs, MaybeReadable, Writer, Writeable, VecWriter};
  33 use util::byte_utils;
  34
  35 use io;
  36 use prelude::*;
  37 use alloc::collections::BTreeMap;
  38 use core::cmp;
  39 use core::ops::Deref;
  40 use core::mem::replace;
  41
  42 const MAX_ALLOC_SIZE: usize = 64*1024;
  43
  44 /// An entry for an [`OnchainEvent`], stating the block height when the event was observed and the
  45 /// transaction causing it.
  46 ///
  47 /// Used to determine when the on-chain event can be considered safe from a chain reorganization.
  48 #[derive(PartialEq)]
  49 struct OnchainEventEntry {
  50         txid: Txid,
  51         height: u32,
  52         event: OnchainEvent,
  53 }
  54
  55 impl OnchainEventEntry {
  56         fn confirmation_threshold(&self) -> u32 {
  57                 self.height + ANTI_REORG_DELAY - 1
  58         }
  59
  60         fn has_reached_confirmation_threshold(&self, height: u32) -> bool {
  61                 height >= self.confirmation_threshold()
  62         }
  63 }
  64
  65 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
  66 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
  67 #[derive(PartialEq)]
  68 enum OnchainEvent {
  69         /// Outpoint under claim process by our own tx, once this one get enough confirmations, we remove it from
  70         /// bump-txn candidate buffer.
  71         Claim {
  72                 claim_request: Txid,
  73         },
  74         /// Claim tx aggregate multiple claimable outpoints. One of the outpoint may be claimed by a counterparty party tx.
  75         /// In this case, we need to drop the outpoint and regenerate a new claim tx. By safety, we keep tracking
  76         /// the outpoint to be sure to resurect it back to the claim tx if reorgs happen.
  77         ContentiousOutpoint {
  78                 package: PackageTemplate,
  79         }
  80 }
  81
  82 impl Writeable for OnchainEventEntry {
  83         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
  84                 write_tlv_fields!(writer, {
  85                         (0, self.txid, required),
  86                         (2, self.height, required),
  87                         (4, self.event, required),
  88                 });
  89                 Ok(())
  90         }
  91 }
  92
  93 impl MaybeReadable for OnchainEventEntry {
  94         fn read<R: io::Read>(reader: &mut R) -> Result<Option<Self>, DecodeError> {
  95                 let mut txid = Default::default();
  96                 let mut height = 0;
  97                 let mut event = None;
  98                 read_tlv_fields!(reader, {
  99                         (0, txid, required),
 100                         (2, height, required),
 101                         (4, event, ignorable),
 102                 });
 103                 if let Some(ev) = event {
 104                         Ok(Some(Self { txid, height, event: ev }))
 105                 } else {
 106                         Ok(None)
 107                 }
 108         }
 109 }
 110
 111 impl_writeable_tlv_based_enum_upgradable!(OnchainEvent,
 112         (0, Claim) => {
 113                 (0, claim_request, required),
 114         },
 115         (1, ContentiousOutpoint) => {
 116                 (0, package, required),
 117         },
 118 );
 119
 120 impl Readable for Option<Vec<Option<(usize, Signature)>>> {
 121         fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
 122                 match Readable::read(reader)? {
 123                         0u8 => Ok(None),
 124                         1u8 => {
 125                                 let vlen: u64 = Readable::read(reader)?;
 126                                 let mut ret = Vec::with_capacity(cmp::min(vlen as usize, MAX_ALLOC_SIZE / ::core::mem::size_of::<Option<(usize, Signature)>>()));
 127                                 for _ in 0..vlen {
 128                                         ret.push(match Readable::read(reader)? {
 129                                                 0u8 => None,
 130                                                 1u8 => Some((<u64 as Readable>::read(reader)? as usize, Readable::read(reader)?)),
 131                                                 _ => return Err(DecodeError::InvalidValue)
 132                                         });
 133                                 }
 134                                 Ok(Some(ret))
 135                         },
 136                         _ => Err(DecodeError::InvalidValue),
 137                 }
 138         }
 139 }
 140
 141 impl Writeable for Option<Vec<Option<(usize, Signature)>>> {
 142         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 143                 match self {
 144                         &Some(ref vec) => {
 145                                 1u8.write(writer)?;
 146                                 (vec.len() as u64).write(writer)?;
 147                                 for opt in vec.iter() {
 148                                         match opt {
 149                                                 &Some((ref idx, ref sig)) => {
 150                                                         1u8.write(writer)?;
 151                                                         (*idx as u64).write(writer)?;
 152                                                         sig.write(writer)?;
 153                                                 },
 154                                                 &None => 0u8.write(writer)?,
 155                                         }
 156                                 }
 157                         },
 158                         &None => 0u8.write(writer)?,
 159                 }
 160                 Ok(())
 161         }
 162 }
 163
 164
 165 /// OnchainTxHandler receives claiming requests, aggregates them if it's sound, broadcast and
 166 /// do RBF bumping if possible.
 167 pub struct OnchainTxHandler<ChannelSigner: Sign> {
 168         destination_script: Script,
 169         holder_commitment: HolderCommitmentTransaction,
 170         // holder_htlc_sigs and prev_holder_htlc_sigs are in the order as they appear in the commitment
 171         // transaction outputs (hence the Option<>s inside the Vec). The first usize is the index in
 172         // the set of HTLCs in the HolderCommitmentTransaction.
 173         holder_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
 174         prev_holder_commitment: Option<HolderCommitmentTransaction>,
 175         prev_holder_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
 176
 177         pub(super) signer: ChannelSigner,
 178         pub(crate) channel_transaction_parameters: ChannelTransactionParameters,
 179
 180         // Used to track claiming requests. If claim tx doesn't confirm before height timer expiration we need to bump
 181         // it (RBF or CPFP). If an input has been part of an aggregate tx at first claim try, we need to keep it within
 182         // another bumped aggregate tx to comply with RBF rules. We may have multiple claiming txn in the flight for the
 183         // same set of outpoints. One of the outpoints may be spent by a transaction not issued by us. That's why at
 184         // block connection we scan all inputs and if any of them is among a set of a claiming request we test for set
 185         // equality between spending transaction and claim request. If true, it means transaction was one our claiming one
 186         // after a security delay of 6 blocks we remove pending claim request. If false, it means transaction wasn't and
 187         // we need to regenerate new claim request with reduced set of still-claimable outpoints.
 188         // Key is identifier of the pending claim request, i.e the txid of the initial claiming transaction generated by
 189         // us and is immutable until all outpoint of the claimable set are post-anti-reorg-delay solved.
 190         // Entry is cache of elements need to generate a bumped claiming transaction (see ClaimTxBumpMaterial)
 191         #[cfg(test)] // Used in functional_test to verify sanitization
 192         pub(crate) pending_claim_requests: HashMap<Txid, PackageTemplate>,
 193         #[cfg(not(test))]
 194         pending_claim_requests: HashMap<Txid, PackageTemplate>,
 195
 196         // Used to link outpoints claimed in a connected block to a pending claim request.
 197         // Key is outpoint than monitor parsing has detected we have keys/scripts to claim
 198         // Value is (pending claim request identifier, confirmation_block), identifier
 199         // is txid of the initial claiming transaction and is immutable until outpoint is
 200         // post-anti-reorg-delay solved, confirmaiton_block is used to erase entry if
 201         // block with output gets disconnected.
 202         #[cfg(test)] // Used in functional_test to verify sanitization
 203         pub claimable_outpoints: HashMap<BitcoinOutPoint, (Txid, u32)>,
 204         #[cfg(not(test))]
 205         claimable_outpoints: HashMap<BitcoinOutPoint, (Txid, u32)>,
 206
 207         locktimed_packages: BTreeMap<u32, Vec<PackageTemplate>>,
 208
 209         onchain_events_awaiting_threshold_conf: Vec<OnchainEventEntry>,
 210
 211         pub(super) secp_ctx: Secp256k1<secp256k1::All>,
 212 }
 213
 214 const SERIALIZATION_VERSION: u8 = 1;
 215 const MIN_SERIALIZATION_VERSION: u8 = 1;
 216
 217 impl<ChannelSigner: Sign> OnchainTxHandler<ChannelSigner> {
 218         pub(crate) fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 219                 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
 220
 221                 self.destination_script.write(writer)?;
 222                 self.holder_commitment.write(writer)?;
 223                 self.holder_htlc_sigs.write(writer)?;
 224                 self.prev_holder_commitment.write(writer)?;
 225                 self.prev_holder_htlc_sigs.write(writer)?;
 226
 227                 self.channel_transaction_parameters.write(writer)?;
 228
 229                 let mut key_data = VecWriter(Vec::new());
 230                 self.signer.write(&mut key_data)?;
 231                 assert!(key_data.0.len() < core::usize::MAX);
 232                 assert!(key_data.0.len() < core::u32::MAX as usize);
 233                 (key_data.0.len() as u32).write(writer)?;
 234                 writer.write_all(&key_data.0[..])?;
 235
 236                 writer.write_all(&byte_utils::be64_to_array(self.pending_claim_requests.len() as u64))?;
 237                 for (ref ancestor_claim_txid, request) in self.pending_claim_requests.iter() {
 238                         ancestor_claim_txid.write(writer)?;
 239                         request.write(writer)?;
 240                 }
 241
 242                 writer.write_all(&byte_utils::be64_to_array(self.claimable_outpoints.len() as u64))?;
 243                 for (ref outp, ref claim_and_height) in self.claimable_outpoints.iter() {
 244                         outp.write(writer)?;
 245                         claim_and_height.0.write(writer)?;
 246                         claim_and_height.1.write(writer)?;
 247                 }
 248
 249                 writer.write_all(&byte_utils::be64_to_array(self.locktimed_packages.len() as u64))?;
 250                 for (ref locktime, ref packages) in self.locktimed_packages.iter() {
 251                         locktime.write(writer)?;
 252                         writer.write_all(&byte_utils::be64_to_array(packages.len() as u64))?;
 253                         for ref package in packages.iter() {
 254                                 package.write(writer)?;
 255                         }
 256                 }
 257
 258                 writer.write_all(&byte_utils::be64_to_array(self.onchain_events_awaiting_threshold_conf.len() as u64))?;
 259                 for ref entry in self.onchain_events_awaiting_threshold_conf.iter() {
 260                         entry.write(writer)?;
 261                 }
 262
 263                 write_tlv_fields!(writer, {});
 264                 Ok(())
 265         }
 266 }
 267
 268 impl<'a, K: KeysInterface> ReadableArgs<&'a K> for OnchainTxHandler<K::Signer> {
 269         fn read<R: io::Read>(reader: &mut R, keys_manager: &'a K) -> Result<Self, DecodeError> {
 270                 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
 271
 272                 let destination_script = Readable::read(reader)?;
 273
 274                 let holder_commitment = Readable::read(reader)?;
 275                 let holder_htlc_sigs = Readable::read(reader)?;
 276                 let prev_holder_commitment = Readable::read(reader)?;
 277                 let prev_holder_htlc_sigs = Readable::read(reader)?;
 278
 279                 let channel_parameters = Readable::read(reader)?;
 280
 281                 let keys_len: u32 = Readable::read(reader)?;
 282                 let mut keys_data = Vec::with_capacity(cmp::min(keys_len as usize, MAX_ALLOC_SIZE));
 283                 while keys_data.len() != keys_len as usize {
 284                         // Read 1KB at a time to avoid accidentally allocating 4GB on corrupted channel keys
 285                         let mut data = [0; 1024];
 286                         let read_slice = &mut data[0..cmp::min(1024, keys_len as usize - keys_data.len())];
 287                         reader.read_exact(read_slice)?;
 288                         keys_data.extend_from_slice(read_slice);
 289                 }
 290                 let signer = keys_manager.read_chan_signer(&keys_data)?;
 291
 292                 let pending_claim_requests_len: u64 = Readable::read(reader)?;
 293                 let mut pending_claim_requests = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
 294                 for _ in 0..pending_claim_requests_len {
 295                         pending_claim_requests.insert(Readable::read(reader)?, Readable::read(reader)?);
 296                 }
 297
 298                 let claimable_outpoints_len: u64 = Readable::read(reader)?;
 299                 let mut claimable_outpoints = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
 300                 for _ in 0..claimable_outpoints_len {
 301                         let outpoint = Readable::read(reader)?;
 302                         let ancestor_claim_txid = Readable::read(reader)?;
 303                         let height = Readable::read(reader)?;
 304                         claimable_outpoints.insert(outpoint, (ancestor_claim_txid, height));
 305                 }
 306
 307                 let locktimed_packages_len: u64 = Readable::read(reader)?;
 308                 let mut locktimed_packages = BTreeMap::new();
 309                 for _ in 0..locktimed_packages_len {
 310                         let locktime = Readable::read(reader)?;
 311                         let packages_len: u64 = Readable::read(reader)?;
 312                         let mut packages = Vec::with_capacity(cmp::min(packages_len as usize, MAX_ALLOC_SIZE / core::mem::size_of::<PackageTemplate>()));
 313                         for _ in 0..packages_len {
 314                                 packages.push(Readable::read(reader)?);
 315                         }
 316                         locktimed_packages.insert(locktime, packages);
 317                 }
 318
 319                 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
 320                 let mut onchain_events_awaiting_threshold_conf = Vec::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
 321                 for _ in 0..waiting_threshold_conf_len {
 322                         if let Some(val) = MaybeReadable::read(reader)? {
 323                                 onchain_events_awaiting_threshold_conf.push(val);
 324                         }
 325                 }
 326
 327                 read_tlv_fields!(reader, {});
 328
 329                 let mut secp_ctx = Secp256k1::new();
 330                 secp_ctx.seeded_randomize(&keys_manager.get_secure_random_bytes());
 331
 332                 Ok(OnchainTxHandler {
 333                         destination_script,
 334                         holder_commitment,
 335                         holder_htlc_sigs,
 336                         prev_holder_commitment,
 337                         prev_holder_htlc_sigs,
 338                         signer,
 339                         channel_transaction_parameters: channel_parameters,
 340                         claimable_outpoints,
 341                         locktimed_packages,
 342                         pending_claim_requests,
 343                         onchain_events_awaiting_threshold_conf,
 344                         secp_ctx,
 345                 })
 346         }
 347 }
 348
 349 impl<ChannelSigner: Sign> OnchainTxHandler<ChannelSigner> {
 350         pub(crate) fn new(destination_script: Script, signer: ChannelSigner, channel_parameters: ChannelTransactionParameters, holder_commitment: HolderCommitmentTransaction, secp_ctx: Secp256k1<secp256k1::All>) -> Self {
 351                 OnchainTxHandler {
 352                         destination_script,
 353                         holder_commitment,
 354                         holder_htlc_sigs: None,
 355                         prev_holder_commitment: None,
 356                         prev_holder_htlc_sigs: None,
 357                         signer,
 358                         channel_transaction_parameters: channel_parameters,
 359                         pending_claim_requests: HashMap::new(),
 360                         claimable_outpoints: HashMap::new(),
 361                         locktimed_packages: BTreeMap::new(),
 362                         onchain_events_awaiting_threshold_conf: Vec::new(),
 363
 364                         secp_ctx,
 365                 }
 366         }
 367
 368         pub(crate) fn get_prev_holder_commitment_to_self_value(&self) -> Option<u64> {
 369                 self.prev_holder_commitment.as_ref().map(|commitment| commitment.to_broadcaster_value_sat())
 370         }
 371
 372         pub(crate) fn get_cur_holder_commitment_to_self_value(&self) -> u64 {
 373                 self.holder_commitment.to_broadcaster_value_sat()
 374         }
 375
 376         /// Lightning security model (i.e being able to redeem/timeout HTLC or penalize coutnerparty onchain) lays on the assumption of claim transactions getting confirmed before timelock expiration
 377         /// (CSV or CLTV following cases). In case of high-fee spikes, claim tx may stuck in the mempool, so you need to bump its feerate quickly using Replace-By-Fee or Child-Pay-For-Parent.
 378         /// Panics if there are signing errors, because signing operations in reaction to on-chain events
 379         /// are not expected to fail, and if they do, we may lose funds.
 380         fn generate_claim_tx<F: Deref, L: Deref>(&mut self, cur_height: u32, cached_request: &PackageTemplate, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L) -> Option<(Option<u32>, u64, Transaction)>
 381                 where F::Target: FeeEstimator,
 382                                         L::Target: Logger,
 383         {
 384                 if cached_request.outpoints().len() == 0 { return None } // But don't prune pending claiming request yet, we may have to resurrect HTLCs
 385
 386                 // Compute new height timer to decide when we need to regenerate a new bumped version of the claim tx (if we
 387                 // didn't receive confirmation of it before, or not enough reorg-safe depth on top of it).
 388                 let new_timer = Some(cached_request.get_height_timer(cur_height));
 389                 if cached_request.is_malleable() {
 390                         let predicted_weight = cached_request.package_weight(&self.destination_script, self.channel_transaction_parameters.opt_anchors.is_some());
 391                         if let Some((output_value, new_feerate)) =
 392                                         cached_request.compute_package_output(predicted_weight, self.destination_script.dust_value().as_sat(), fee_estimator, logger) {
 393                                 assert!(new_feerate != 0);
 394
 395                                 let transaction = cached_request.finalize_package(self, output_value, self.destination_script.clone(), logger).unwrap();
 396                                 log_trace!(logger, "...with timer {} and feerate {}", new_timer.unwrap(), new_feerate);
 397                                 assert!(predicted_weight >= transaction.weight());
 398                                 return Some((new_timer, new_feerate, transaction))
 399                         }
 400                 } else {
 401                         // Note: Currently, amounts of holder outputs spending witnesses aren't used
 402                         // as we can't malleate spending package to increase their feerate. This
 403                         // should change with the remaining anchor output patchset.
 404                         if let Some(transaction) = cached_request.finalize_package(self, 0, self.destination_script.clone(), logger) {
 405                                 return Some((None, 0, transaction));
 406                         }
 407                 }
 408                 None
 409         }
 410
 411         /// Upon channelmonitor.block_connected(..) or upon provision of a preimage on the forward link
 412         /// for this channel, provide new relevant on-chain transactions and/or new claim requests.
 413         /// Formerly this was named `block_connected`, but it is now also used for claiming an HTLC output
 414         /// if we receive a preimage after force-close.
 415         /// `conf_height` represents the height at which the transactions in `txn_matched` were
 416         /// confirmed. This does not need to equal the current blockchain tip height, which should be
 417         /// provided via `cur_height`, however it must never be higher than `cur_height`.
 418         pub(crate) fn update_claims_view<B: Deref, F: Deref, L: Deref>(&mut self, txn_matched: &[&Transaction], requests: Vec<PackageTemplate>, conf_height: u32, cur_height: u32, broadcaster: &B, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L)
 419                 where B::Target: BroadcasterInterface,
 420                       F::Target: FeeEstimator,
 421                                         L::Target: Logger,
 422         {
 423                 log_debug!(logger, "Updating claims view at height {} with {} matched transactions in block {} and {} claim requests", cur_height, txn_matched.len(), conf_height, requests.len());
 424                 let mut preprocessed_requests = Vec::with_capacity(requests.len());
 425                 let mut aggregated_request = None;
 426
 427                 // Try to aggregate outputs if their timelock expiration isn't imminent (package timelock
 428                 // <= CLTV_SHARED_CLAIM_BUFFER) and they don't require an immediate nLockTime (aggregable).
 429                 for req in requests {
 430                         // Don't claim a outpoint twice that would be bad for privacy and may uselessly lock a CPFP input for a while
 431                         if let Some(_) = self.claimable_outpoints.get(req.outpoints()[0]) {
 432                                 log_info!(logger, "Ignoring second claim for outpoint {}:{}, already registered its claiming request", req.outpoints()[0].txid, req.outpoints()[0].vout);
 433                         } else {
 434                                 let timelocked_equivalent_package = self.locktimed_packages.iter().map(|v| v.1.iter()).flatten()
 435                                         .find(|locked_package| locked_package.outpoints() == req.outpoints());
 436                                 if let Some(package) = timelocked_equivalent_package {
 437                                         log_info!(logger, "Ignoring second claim for outpoint {}:{}, we already have one which we're waiting on a timelock at {} for.",
 438                                                 req.outpoints()[0].txid, req.outpoints()[0].vout, package.package_timelock());
 439                                         continue;
 440                                 }
 441
 442                                 if req.package_timelock() > cur_height + 1 {
 443                                         log_info!(logger, "Delaying claim of package until its timelock at {} (current height {}), the following outpoints are spent:", req.package_timelock(), cur_height);
 444                                         for outpoint in req.outpoints() {
 445                                                 log_info!(logger, "  Outpoint {}", outpoint);
 446                                         }
 447                                         self.locktimed_packages.entry(req.package_timelock()).or_insert(Vec::new()).push(req);
 448                                         continue;
 449                                 }
 450
 451                                 log_trace!(logger, "Test if outpoint can be aggregated with expiration {} against {}", req.timelock(), cur_height + CLTV_SHARED_CLAIM_BUFFER);
 452                                 if req.timelock() <= cur_height + CLTV_SHARED_CLAIM_BUFFER || !req.aggregable() {
 453                                         // Don't aggregate if outpoint package timelock is soon or marked as non-aggregable
 454                                         preprocessed_requests.push(req);
 455                                 } else if aggregated_request.is_none() {
 456                                         aggregated_request = Some(req);
 457                                 } else {
 458                                         aggregated_request.as_mut().unwrap().merge_package(req);
 459                                 }
 460                         }
 461                 }
 462                 if let Some(req) = aggregated_request {
 463                         preprocessed_requests.push(req);
 464                 }
 465
 466                 // Claim everything up to and including cur_height + 1
 467                 let remaining_locked_packages = self.locktimed_packages.split_off(&(cur_height + 2));
 468                 for (pop_height, mut entry) in self.locktimed_packages.iter_mut() {
 469                         log_trace!(logger, "Restoring delayed claim of package(s) at their timelock at {}.", pop_height);
 470                         preprocessed_requests.append(&mut entry);
 471                 }
 472                 self.locktimed_packages = remaining_locked_packages;
 473
 474                 // Generate claim transactions and track them to bump if necessary at
 475                 // height timer expiration (i.e in how many blocks we're going to take action).
 476                 for mut req in preprocessed_requests {
 477                         if let Some((new_timer, new_feerate, tx)) = self.generate_claim_tx(cur_height, &req, &*fee_estimator, &*logger) {
 478                                 req.set_timer(new_timer);
 479                                 req.set_feerate(new_feerate);
 480                                 let txid = tx.txid();
 481                                 for k in req.outpoints() {
 482                                         log_info!(logger, "Registering claiming request for {}:{}", k.txid, k.vout);
 483                                         self.claimable_outpoints.insert(k.clone(), (txid, conf_height));
 484                                 }
 485                                 self.pending_claim_requests.insert(txid, req);
 486                                 log_info!(logger, "Broadcasting onchain {}", log_tx!(tx));
 487                                 broadcaster.broadcast_transaction(&tx);
 488                         }
 489                 }
 490
 491                 let mut bump_candidates = HashMap::new();
 492                 for tx in txn_matched {
 493                         // Scan all input to verify is one of the outpoint spent is of interest for us
 494                         let mut claimed_outputs_material = Vec::new();
 495                         for inp in &tx.input {
 496                                 if let Some(first_claim_txid_height) = self.claimable_outpoints.get(&inp.previous_output) {
 497                                         // If outpoint has claim request pending on it...
 498                                         if let Some(request) = self.pending_claim_requests.get_mut(&first_claim_txid_height.0) {
 499                                                 //... we need to verify equality between transaction outpoints and claim request
 500                                                 // outpoints to know if transaction is the original claim or a bumped one issued
 501                                                 // by us.
 502                                                 let mut set_equality = true;
 503                                                 if request.outpoints().len() != tx.input.len() {
 504                                                         set_equality = false;
 505                                                 } else {
 506                                                         for (claim_inp, tx_inp) in request.outpoints().iter().zip(tx.input.iter()) {
 507                                                                 if **claim_inp != tx_inp.previous_output {
 508                                                                         set_equality = false;
 509                                                                 }
 510                                                         }
 511                                                 }
 512
 513                                                 macro_rules! clean_claim_request_after_safety_delay {
 514                                                         () => {
 515                                                                 let entry = OnchainEventEntry {
 516                                                                         txid: tx.txid(),
 517                                                                         height: conf_height,
 518                                                                         event: OnchainEvent::Claim { claim_request: first_claim_txid_height.0.clone() }
 519                                                                 };
 520                                                                 if !self.onchain_events_awaiting_threshold_conf.contains(&entry) {
 521                                                                         self.onchain_events_awaiting_threshold_conf.push(entry);
 522                                                                 }
 523                                                         }
 524                                                 }
 525
 526                                                 // If this is our transaction (or our counterparty spent all the outputs
 527                                                 // before we could anyway with same inputs order than us), wait for
 528                                                 // ANTI_REORG_DELAY and clean the RBF tracking map.
 529                                                 if set_equality {
 530                                                         clean_claim_request_after_safety_delay!();
 531                                                 } else { // If false, generate new claim request with update outpoint set
 532                                                         let mut at_least_one_drop = false;
 533                                                         for input in tx.input.iter() {
 534                                                                 if let Some(package) = request.split_package(&input.previous_output) {
 535                                                                         claimed_outputs_material.push(package);
 536                                                                         at_least_one_drop = true;
 537                                                                 }
 538                                                                 // If there are no outpoints left to claim in this request, drop it entirely after ANTI_REORG_DELAY.
 539                                                                 if request.outpoints().is_empty() {
 540                                                                         clean_claim_request_after_safety_delay!();
 541                                                                 }
 542                                                         }
 543                                                         //TODO: recompute soonest_timelock to avoid wasting a bit on fees
 544                                                         if at_least_one_drop {
 545                                                                 bump_candidates.insert(first_claim_txid_height.0.clone(), request.clone());
 546                                                         }
 547                                                 }
 548                                                 break; //No need to iterate further, either tx is our or their
 549                                         } else {
 550                                                 panic!("Inconsistencies between pending_claim_requests map and claimable_outpoints map");
 551                                         }
 552                                 }
 553                         }
 554                         for package in claimed_outputs_material.drain(..) {
 555                                 let entry = OnchainEventEntry {
 556                                         txid: tx.txid(),
 557                                         height: conf_height,
 558                                         event: OnchainEvent::ContentiousOutpoint { package },
 559                                 };
 560                                 if !self.onchain_events_awaiting_threshold_conf.contains(&entry) {
 561                                         self.onchain_events_awaiting_threshold_conf.push(entry);
 562                                 }
 563                         }
 564                 }
 565
 566                 // After security delay, either our claim tx got enough confs or outpoint is definetely out of reach
 567                 let onchain_events_awaiting_threshold_conf =
 568                         self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
 569                 for entry in onchain_events_awaiting_threshold_conf {
 570                         if entry.has_reached_confirmation_threshold(cur_height) {
 571                                 match entry.event {
 572                                         OnchainEvent::Claim { claim_request } => {
 573                                                 // We may remove a whole set of claim outpoints here, as these one may have
 574                                                 // been aggregated in a single tx and claimed so atomically
 575                                                 if let Some(request) = self.pending_claim_requests.remove(&claim_request) {
 576                                                         for outpoint in request.outpoints() {
 577                                                                 log_debug!(logger, "Removing claim tracking for {} due to maturation of claim tx {}.", outpoint, claim_request);
 578                                                                 self.claimable_outpoints.remove(&outpoint);
 579                                                         }
 580                                                 }
 581                                         },
 582                                         OnchainEvent::ContentiousOutpoint { package } => {
 583                                                 log_debug!(logger, "Removing claim tracking due to maturation of claim tx for outpoints:");
 584                                                 log_debug!(logger, " {:?}", package.outpoints());
 585                                                 self.claimable_outpoints.remove(&package.outpoints()[0]);
 586                                         }
 587                                 }
 588                         } else {
 589                                 self.onchain_events_awaiting_threshold_conf.push(entry);
 590                         }
 591                 }
 592
 593                 // Check if any pending claim request must be rescheduled
 594                 for (first_claim_txid, ref request) in self.pending_claim_requests.iter() {
 595                         if let Some(h) = request.timer() {
 596                                 if cur_height >= h {
 597                                         bump_candidates.insert(*first_claim_txid, (*request).clone());
 598                                 }
 599                         }
 600                 }
 601
 602                 // Build, bump and rebroadcast tx accordingly
 603                 log_trace!(logger, "Bumping {} candidates", bump_candidates.len());
 604                 for (first_claim_txid, request) in bump_candidates.iter() {
 605                         if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(cur_height, &request, &*fee_estimator, &*logger) {
 606                                 log_info!(logger, "Broadcasting RBF-bumped onchain {}", log_tx!(bump_tx));
 607                                 broadcaster.broadcast_transaction(&bump_tx);
 608                                 if let Some(request) = self.pending_claim_requests.get_mut(first_claim_txid) {
 609                                         request.set_timer(new_timer);
 610                                         request.set_feerate(new_feerate);
 611                                 }
 612                         }
 613                 }
 614         }
 615
 616         pub(crate) fn transaction_unconfirmed<B: Deref, F: Deref, L: Deref>(
 617                 &mut self,
 618                 txid: &Txid,
 619                 broadcaster: B,
 620                 fee_estimator: &LowerBoundedFeeEstimator<F>,
 621                 logger: L,
 622         ) where
 623                 B::Target: BroadcasterInterface,
 624                 F::Target: FeeEstimator,
 625                 L::Target: Logger,
 626         {
 627                 let mut height = None;
 628                 for entry in self.onchain_events_awaiting_threshold_conf.iter() {
 629                         if entry.txid == *txid {
 630                                 height = Some(entry.height);
 631                                 break;
 632                         }
 633                 }
 634
 635                 if let Some(height) = height {
 636                         self.block_disconnected(height, broadcaster, fee_estimator, logger);
 637                 }
 638         }
 639
 640         pub(crate) fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, height: u32, broadcaster: B, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: L)
 641                 where B::Target: BroadcasterInterface,
 642                       F::Target: FeeEstimator,
 643                                         L::Target: Logger,
 644         {
 645                 let mut bump_candidates = HashMap::new();
 646                 let onchain_events_awaiting_threshold_conf =
 647                         self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
 648                 for entry in onchain_events_awaiting_threshold_conf {
 649                         if entry.height >= height {
 650                                 //- our claim tx on a commitment tx output
 651                                 //- resurect outpoint back in its claimable set and regenerate tx
 652                                 match entry.event {
 653                                         OnchainEvent::ContentiousOutpoint { package } => {
 654                                                 if let Some(ancestor_claimable_txid) = self.claimable_outpoints.get(&package.outpoints()[0]) {
 655                                                         if let Some(request) = self.pending_claim_requests.get_mut(&ancestor_claimable_txid.0) {
 656                                                                 request.merge_package(package);
 657                                                                 // Using a HashMap guarantee us than if we have multiple outpoints getting
 658                                                                 // resurrected only one bump claim tx is going to be broadcast
 659                                                                 bump_candidates.insert(ancestor_claimable_txid.clone(), request.clone());
 660                                                         }
 661                                                 }
 662                                         },
 663                                         _ => {},
 664                                 }
 665                         } else {
 666                                 self.onchain_events_awaiting_threshold_conf.push(entry);
 667                         }
 668                 }
 669                 for (_, request) in bump_candidates.iter_mut() {
 670                         if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &request, fee_estimator, &&*logger) {
 671                                 request.set_timer(new_timer);
 672                                 request.set_feerate(new_feerate);
 673                                 log_info!(logger, "Broadcasting onchain {}", log_tx!(bump_tx));
 674                                 broadcaster.broadcast_transaction(&bump_tx);
 675                         }
 676                 }
 677                 for (ancestor_claim_txid, request) in bump_candidates.drain() {
 678                         self.pending_claim_requests.insert(ancestor_claim_txid.0, request);
 679                 }
 680                 //TODO: if we implement cross-block aggregated claim transaction we need to refresh set of outpoints and regenerate tx but
 681                 // right now if one of the outpoint get disconnected, just erase whole pending claim request.
 682                 let mut remove_request = Vec::new();
 683                 self.claimable_outpoints.retain(|_, ref v|
 684                         if v.1 >= height {
 685                         remove_request.push(v.0.clone());
 686                         false
 687                         } else { true });
 688                 for req in remove_request {
 689                         self.pending_claim_requests.remove(&req);
 690                 }
 691         }
 692
 693         pub(crate) fn get_relevant_txids(&self) -> Vec<Txid> {
 694                 let mut txids: Vec<Txid> = self.onchain_events_awaiting_threshold_conf
 695                         .iter()
 696                         .map(|entry| entry.txid)
 697                         .collect();
 698                 txids.sort_unstable();
 699                 txids.dedup();
 700                 txids
 701         }
 702
 703         pub(crate) fn provide_latest_holder_tx(&mut self, tx: HolderCommitmentTransaction) {
 704                 self.prev_holder_commitment = Some(replace(&mut self.holder_commitment, tx));
 705                 self.holder_htlc_sigs = None;
 706         }
 707
 708         // Normally holder HTLCs are signed at the same time as the holder commitment tx.  However,
 709         // in some configurations, the holder commitment tx has been signed and broadcast by a
 710         // ChannelMonitor replica, so we handle that case here.
 711         fn sign_latest_holder_htlcs(&mut self) {
 712                 if self.holder_htlc_sigs.is_none() {
 713                         let (_sig, sigs) = self.signer.sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("sign holder commitment");
 714                         self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, sigs));
 715                 }
 716         }
 717
 718         // Normally only the latest commitment tx and HTLCs need to be signed.  However, in some
 719         // configurations we may have updated our holder commitment but a replica of the ChannelMonitor
 720         // broadcast the previous one before we sync with it.  We handle that case here.
 721         fn sign_prev_holder_htlcs(&mut self) {
 722                 if self.prev_holder_htlc_sigs.is_none() {
 723                         if let Some(ref holder_commitment) = self.prev_holder_commitment {
 724                                 let (_sig, sigs) = self.signer.sign_holder_commitment_and_htlcs(holder_commitment, &self.secp_ctx).expect("sign previous holder commitment");
 725                                 self.prev_holder_htlc_sigs = Some(Self::extract_holder_sigs(holder_commitment, sigs));
 726                         }
 727                 }
 728         }
 729
 730         fn extract_holder_sigs(holder_commitment: &HolderCommitmentTransaction, sigs: Vec<Signature>) -> Vec<Option<(usize, Signature)>> {
 731                 let mut ret = Vec::new();
 732                 for (htlc_idx, (holder_sig, htlc)) in sigs.iter().zip(holder_commitment.htlcs().iter()).enumerate() {
 733                         let tx_idx = htlc.transaction_output_index.unwrap();
 734                         if ret.len() <= tx_idx as usize { ret.resize(tx_idx as usize + 1, None); }
 735                         ret[tx_idx as usize] = Some((htlc_idx, holder_sig.clone()));
 736                 }
 737                 ret
 738         }
 739
 740         //TODO: getting lastest holder transactions should be infallible and result in us "force-closing the channel", but we may
 741         // have empty holder commitment transaction if a ChannelMonitor is asked to force-close just after Channel::get_outbound_funding_created,
 742         // before providing a initial commitment transaction. For outbound channel, init ChannelMonitor at Channel::funding_signed, there is nothing
 743         // to monitor before.
 744         pub(crate) fn get_fully_signed_holder_tx(&mut self, funding_redeemscript: &Script) -> Transaction {
 745                 let (sig, htlc_sigs) = self.signer.sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("signing holder commitment");
 746                 self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, htlc_sigs));
 747                 self.holder_commitment.add_holder_sig(funding_redeemscript, sig)
 748         }
 749
 750         #[cfg(any(test, feature="unsafe_revoked_tx_signing"))]
 751         pub(crate) fn get_fully_signed_copy_holder_tx(&mut self, funding_redeemscript: &Script) -> Transaction {
 752                 let (sig, htlc_sigs) = self.signer.unsafe_sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("sign holder commitment");
 753                 self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, htlc_sigs));
 754                 self.holder_commitment.add_holder_sig(funding_redeemscript, sig)
 755         }
 756
 757         pub(crate) fn get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
 758                 let mut htlc_tx = None;
 759                 let commitment_txid = self.holder_commitment.trust().txid();
 760                 // Check if the HTLC spends from the current holder commitment
 761                 if commitment_txid == outp.txid {
 762                         self.sign_latest_holder_htlcs();
 763                         if let &Some(ref htlc_sigs) = &self.holder_htlc_sigs {
 764                                 let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
 765                                 let trusted_tx = self.holder_commitment.trust();
 766                                 let counterparty_htlc_sig = self.holder_commitment.counterparty_htlc_sigs[*htlc_idx];
 767                                 htlc_tx = Some(trusted_tx
 768                                         .get_signed_htlc_tx(&self.channel_transaction_parameters.as_holder_broadcastable(), *htlc_idx, &counterparty_htlc_sig, htlc_sig, preimage));
 769                         }
 770                 }
 771                 // If the HTLC doesn't spend the current holder commitment, check if it spends the previous one
 772                 if htlc_tx.is_none() && self.prev_holder_commitment.is_some() {
 773                         let commitment_txid = self.prev_holder_commitment.as_ref().unwrap().trust().txid();
 774                         if commitment_txid == outp.txid {
 775                                 self.sign_prev_holder_htlcs();
 776                                 if let &Some(ref htlc_sigs) = &self.prev_holder_htlc_sigs {
 777                                         let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
 778                                         let holder_commitment = self.prev_holder_commitment.as_ref().unwrap();
 779                                         let trusted_tx = holder_commitment.trust();
 780                                         let counterparty_htlc_sig = holder_commitment.counterparty_htlc_sigs[*htlc_idx];
 781                                         htlc_tx = Some(trusted_tx
 782                                                 .get_signed_htlc_tx(&self.channel_transaction_parameters.as_holder_broadcastable(), *htlc_idx, &counterparty_htlc_sig, htlc_sig, preimage));
 783                                 }
 784                         }
 785                 }
 786                 htlc_tx
 787         }
 788
 789         pub(crate) fn opt_anchors(&self) -> bool {
 790                 self.channel_transaction_parameters.opt_anchors.is_some()
 791         }
 792
 793         #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
 794         pub(crate) fn unsafe_get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
 795                 let latest_had_sigs = self.holder_htlc_sigs.is_some();
 796                 let prev_had_sigs = self.prev_holder_htlc_sigs.is_some();
 797                 let ret = self.get_fully_signed_htlc_tx(outp, preimage);
 798                 if !latest_had_sigs {
 799                         self.holder_htlc_sigs = None;
 800                 }
 801                 if !prev_had_sigs {
 802                         self.prev_holder_htlc_sigs = None;
 803                 }
 804                 ret
 805         }
 806 }