_ 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(Clone, 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(Clone, 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 #[derive(Clone, PartialEq, Eq)]
 176 pub(crate) struct ExternalHTLCClaim {
 177         pub(crate) commitment_txid: Txid,
 178         pub(crate) per_commitment_number: u64,
 179         pub(crate) htlc: HTLCOutputInCommitment,
 180         pub(crate) preimage: Option<PaymentPreimage>,
 181         pub(crate) counterparty_sig: Signature,
 182 }
 183
 184 // Represents the different types of claims for which events are yielded externally to satisfy said
 185 // claims.
 186 #[derive(Clone, PartialEq, Eq)]
 187 pub(crate) enum ClaimEvent {
 188         /// Event yielded to signal that the commitment transaction fee must be bumped to claim any
 189         /// encumbered funds and proceed to HTLC resolution, if any HTLCs exist.
 190         BumpCommitment {
 191                 package_target_feerate_sat_per_1000_weight: u32,
 192                 commitment_tx: Transaction,
 193                 anchor_output_idx: u32,
 194         },
 195         /// Event yielded to signal that the commitment transaction has confirmed and its HTLCs must be
 196         /// resolved by broadcasting a transaction with sufficient fee to claim them.
 197         BumpHTLC {
 198                 target_feerate_sat_per_1000_weight: u32,
 199                 htlcs: Vec<ExternalHTLCClaim>,
 200                 tx_lock_time: PackedLockTime,
 201         },
 202 }
 203
 204 /// Represents the different ways an output can be claimed (i.e., spent to an address under our
 205 /// control) onchain.
 206 pub(crate) enum OnchainClaim {
 207         /// A finalized transaction pending confirmation spending the output to claim.
 208         Tx(Transaction),
 209         /// An event yielded externally to signal additional inputs must be added to a transaction
 210         /// pending confirmation spending the output to claim.
 211         Event(ClaimEvent),
 212 }
 213
 214 /// OnchainTxHandler receives claiming requests, aggregates them if it's sound, broadcast and
 215 /// do RBF bumping if possible.
 216 #[derive(Clone)]
 217 pub struct OnchainTxHandler<ChannelSigner: WriteableEcdsaChannelSigner> {
 218         channel_value_satoshis: u64,
 219         channel_keys_id: [u8; 32],
 220         destination_script: Script,
 221         holder_commitment: HolderCommitmentTransaction,
 222         // holder_htlc_sigs and prev_holder_htlc_sigs are in the order as they appear in the commitment
 223         // transaction outputs (hence the Option<>s inside the Vec). The first usize is the index in
 224         // the set of HTLCs in the HolderCommitmentTransaction.
 225         holder_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
 226         prev_holder_commitment: Option<HolderCommitmentTransaction>,
 227         prev_holder_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
 228
 229         pub(super) signer: ChannelSigner,
 230         pub(crate) channel_transaction_parameters: ChannelTransactionParameters,
 231
 232         // Used to track claiming requests. If claim tx doesn't confirm before height timer expiration we need to bump
 233         // it (RBF or CPFP). If an input has been part of an aggregate tx at first claim try, we need to keep it within
 234         // another bumped aggregate tx to comply with RBF rules. We may have multiple claiming txn in the flight for the
 235         // same set of outpoints. One of the outpoints may be spent by a transaction not issued by us. That's why at
 236         // block connection we scan all inputs and if any of them is among a set of a claiming request we test for set
 237         // equality between spending transaction and claim request. If true, it means transaction was one our claiming one
 238         // after a security delay of 6 blocks we remove pending claim request. If false, it means transaction wasn't and
 239         // we need to regenerate new claim request with reduced set of still-claimable outpoints.
 240         // Key is identifier of the pending claim request, i.e the txid of the initial claiming transaction generated by
 241         // us and is immutable until all outpoint of the claimable set are post-anti-reorg-delay solved.
 242         // Entry is cache of elements need to generate a bumped claiming transaction (see ClaimTxBumpMaterial)
 243         #[cfg(test)] // Used in functional_test to verify sanitization
 244         pub(crate) pending_claim_requests: HashMap<ClaimId, PackageTemplate>,
 245         #[cfg(not(test))]
 246         pending_claim_requests: HashMap<ClaimId, PackageTemplate>,
 247
 248         // Used to track external events that need to be forwarded to the `ChainMonitor`. This `Vec`
 249         // essentially acts as an insertion-ordered `HashMap` – there should only ever be one occurrence
 250         // of a `ClaimId`, which tracks its latest `ClaimEvent`, i.e., if a pending claim exists, and
 251         // a new block has been connected, resulting in a new claim, the previous will be replaced with
 252         // the new.
 253         //
 254         // These external events may be generated in the following cases:
 255         //      - A channel has been force closed by broadcasting the holder's latest commitment transaction
 256         //      - A block being connected/disconnected
 257         //      - Learning the preimage for an HTLC we can claim onchain
 258         pending_claim_events: Vec<(ClaimId, ClaimEvent)>,
 259
 260         // Used to link outpoints claimed in a connected block to a pending claim request. The keys
 261         // represent the outpoints that our `ChannelMonitor` has detected we have keys/scripts to
 262         // claim. The values track the pending claim request identifier and the initial confirmation
 263         // block height, and are immutable until the outpoint has enough confirmations to meet our
 264         // [`ANTI_REORG_DELAY`]. The initial confirmation block height is used to remove the entry if
 265         // the block gets disconnected.
 266         #[cfg(test)] // Used in functional_test to verify sanitization
 267         pub claimable_outpoints: HashMap<BitcoinOutPoint, (ClaimId, u32)>,
 268         #[cfg(not(test))]
 269         claimable_outpoints: HashMap<BitcoinOutPoint, (ClaimId, u32)>,
 270
 271         locktimed_packages: BTreeMap<u32, Vec<PackageTemplate>>,
 272
 273         onchain_events_awaiting_threshold_conf: Vec<OnchainEventEntry>,
 274
 275         pub(super) secp_ctx: Secp256k1<secp256k1::All>,
 276 }
 277
 278 impl<ChannelSigner: WriteableEcdsaChannelSigner> PartialEq for OnchainTxHandler<ChannelSigner> {
 279         fn eq(&self, other: &Self) -> bool {
 280                 // `signer`, `secp_ctx`, and `pending_claim_events` are excluded on purpose.
 281                 self.channel_value_satoshis == other.channel_value_satoshis &&
 282                         self.channel_keys_id == other.channel_keys_id &&
 283                         self.destination_script == other.destination_script &&
 284                         self.holder_commitment == other.holder_commitment &&
 285                         self.holder_htlc_sigs == other.holder_htlc_sigs &&
 286                         self.prev_holder_commitment == other.prev_holder_commitment &&
 287                         self.prev_holder_htlc_sigs == other.prev_holder_htlc_sigs &&
 288                         self.channel_transaction_parameters == other.channel_transaction_parameters &&
 289                         self.pending_claim_requests == other.pending_claim_requests &&
 290                         self.claimable_outpoints == other.claimable_outpoints &&
 291                         self.locktimed_packages == other.locktimed_packages &&
 292                         self.onchain_events_awaiting_threshold_conf == other.onchain_events_awaiting_threshold_conf
 293         }
 294 }
 295
 296 const SERIALIZATION_VERSION: u8 = 1;
 297 const MIN_SERIALIZATION_VERSION: u8 = 1;
 298
 299 impl<ChannelSigner: WriteableEcdsaChannelSigner> OnchainTxHandler<ChannelSigner> {
 300         pub(crate) fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 301                 write_ver_prefix!(writer, SERIALIZATION_VERSION, MIN_SERIALIZATION_VERSION);
 302
 303                 self.destination_script.write(writer)?;
 304                 self.holder_commitment.write(writer)?;
 305                 self.holder_htlc_sigs.write(writer)?;
 306                 self.prev_holder_commitment.write(writer)?;
 307                 self.prev_holder_htlc_sigs.write(writer)?;
 308
 309                 self.channel_transaction_parameters.write(writer)?;
 310
 311                 let mut key_data = VecWriter(Vec::new());
 312                 self.signer.write(&mut key_data)?;
 313                 assert!(key_data.0.len() < core::usize::MAX);
 314                 assert!(key_data.0.len() < core::u32::MAX as usize);
 315                 (key_data.0.len() as u32).write(writer)?;
 316                 writer.write_all(&key_data.0[..])?;
 317
 318                 writer.write_all(&(self.pending_claim_requests.len() as u64).to_be_bytes())?;
 319                 for (ref ancestor_claim_txid, request) in self.pending_claim_requests.iter() {
 320                         ancestor_claim_txid.write(writer)?;
 321                         request.write(writer)?;
 322                 }
 323
 324                 writer.write_all(&(self.claimable_outpoints.len() as u64).to_be_bytes())?;
 325                 for (ref outp, ref claim_and_height) in self.claimable_outpoints.iter() {
 326                         outp.write(writer)?;
 327                         claim_and_height.0.write(writer)?;
 328                         claim_and_height.1.write(writer)?;
 329                 }
 330
 331                 writer.write_all(&(self.locktimed_packages.len() as u64).to_be_bytes())?;
 332                 for (ref locktime, ref packages) in self.locktimed_packages.iter() {
 333                         locktime.write(writer)?;
 334                         writer.write_all(&(packages.len() as u64).to_be_bytes())?;
 335                         for ref package in packages.iter() {
 336                                 package.write(writer)?;
 337                         }
 338                 }
 339
 340                 writer.write_all(&(self.onchain_events_awaiting_threshold_conf.len() as u64).to_be_bytes())?;
 341                 for ref entry in self.onchain_events_awaiting_threshold_conf.iter() {
 342                         entry.write(writer)?;
 343                 }
 344
 345                 write_tlv_fields!(writer, {});
 346                 Ok(())
 347         }
 348 }
 349
 350 impl<'a, 'b, ES: EntropySource, SP: SignerProvider> ReadableArgs<(&'a ES, &'b SP, u64, [u8; 32])> for OnchainTxHandler<SP::Signer> {
 351         fn read<R: io::Read>(reader: &mut R, args: (&'a ES, &'b SP, u64, [u8; 32])) -> Result<Self, DecodeError> {
 352                 let entropy_source = args.0;
 353                 let signer_provider = args.1;
 354                 let channel_value_satoshis = args.2;
 355                 let channel_keys_id = args.3;
 356
 357                 let _ver = read_ver_prefix!(reader, SERIALIZATION_VERSION);
 358
 359                 let destination_script = Readable::read(reader)?;
 360
 361                 let holder_commitment = Readable::read(reader)?;
 362                 let holder_htlc_sigs = Readable::read(reader)?;
 363                 let prev_holder_commitment = Readable::read(reader)?;
 364                 let prev_holder_htlc_sigs = Readable::read(reader)?;
 365
 366                 let channel_parameters = Readable::read(reader)?;
 367
 368                 // Read the serialized signer bytes, but don't deserialize them, as we'll obtain our signer
 369                 // by re-deriving the private key material.
 370                 let keys_len: u32 = Readable::read(reader)?;
 371                 let mut bytes_read = 0;
 372                 while bytes_read != keys_len as usize {
 373                         // Read 1KB at a time to avoid accidentally allocating 4GB on corrupted channel keys
 374                         let mut data = [0; 1024];
 375                         let bytes_to_read = cmp::min(1024, keys_len as usize - bytes_read);
 376                         let read_slice = &mut data[0..bytes_to_read];
 377                         reader.read_exact(read_slice)?;
 378                         bytes_read += bytes_to_read;
 379                 }
 380
 381                 let mut signer = signer_provider.derive_channel_signer(channel_value_satoshis, channel_keys_id);
 382                 signer.provide_channel_parameters(&channel_parameters);
 383
 384                 let pending_claim_requests_len: u64 = Readable::read(reader)?;
 385                 let mut pending_claim_requests = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
 386                 for _ in 0..pending_claim_requests_len {
 387                         pending_claim_requests.insert(Readable::read(reader)?, Readable::read(reader)?);
 388                 }
 389
 390                 let claimable_outpoints_len: u64 = Readable::read(reader)?;
 391                 let mut claimable_outpoints = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
 392                 for _ in 0..claimable_outpoints_len {
 393                         let outpoint = Readable::read(reader)?;
 394                         let ancestor_claim_txid = Readable::read(reader)?;
 395                         let height = Readable::read(reader)?;
 396                         claimable_outpoints.insert(outpoint, (ancestor_claim_txid, height));
 397                 }
 398
 399                 let locktimed_packages_len: u64 = Readable::read(reader)?;
 400                 let mut locktimed_packages = BTreeMap::new();
 401                 for _ in 0..locktimed_packages_len {
 402                         let locktime = Readable::read(reader)?;
 403                         let packages_len: u64 = Readable::read(reader)?;
 404                         let mut packages = Vec::with_capacity(cmp::min(packages_len as usize, MAX_ALLOC_SIZE / core::mem::size_of::<PackageTemplate>()));
 405                         for _ in 0..packages_len {
 406                                 packages.push(Readable::read(reader)?);
 407                         }
 408                         locktimed_packages.insert(locktime, packages);
 409                 }
 410
 411                 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
 412                 let mut onchain_events_awaiting_threshold_conf = Vec::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
 413                 for _ in 0..waiting_threshold_conf_len {
 414                         if let Some(val) = MaybeReadable::read(reader)? {
 415                                 onchain_events_awaiting_threshold_conf.push(val);
 416                         }
 417                 }
 418
 419                 read_tlv_fields!(reader, {});
 420
 421                 let mut secp_ctx = Secp256k1::new();
 422                 secp_ctx.seeded_randomize(&entropy_source.get_secure_random_bytes());
 423
 424                 Ok(OnchainTxHandler {
 425                         channel_value_satoshis,
 426                         channel_keys_id,
 427                         destination_script,
 428                         holder_commitment,
 429                         holder_htlc_sigs,
 430                         prev_holder_commitment,
 431                         prev_holder_htlc_sigs,
 432                         signer,
 433                         channel_transaction_parameters: channel_parameters,
 434                         claimable_outpoints,
 435                         locktimed_packages,
 436                         pending_claim_requests,
 437                         onchain_events_awaiting_threshold_conf,
 438                         pending_claim_events: Vec::new(),
 439                         secp_ctx,
 440                 })
 441         }
 442 }
 443
 444 impl<ChannelSigner: WriteableEcdsaChannelSigner> OnchainTxHandler<ChannelSigner> {
 445         pub(crate) fn new(
 446                 channel_value_satoshis: u64, channel_keys_id: [u8; 32], destination_script: Script,
 447                 signer: ChannelSigner, channel_parameters: ChannelTransactionParameters,
 448                 holder_commitment: HolderCommitmentTransaction, secp_ctx: Secp256k1<secp256k1::All>
 449         ) -> Self {
 450                 OnchainTxHandler {
 451                         channel_value_satoshis,
 452                         channel_keys_id,
 453                         destination_script,
 454                         holder_commitment,
 455                         holder_htlc_sigs: None,
 456                         prev_holder_commitment: None,
 457                         prev_holder_htlc_sigs: None,
 458                         signer,
 459                         channel_transaction_parameters: channel_parameters,
 460                         pending_claim_requests: HashMap::new(),
 461                         claimable_outpoints: HashMap::new(),
 462                         locktimed_packages: BTreeMap::new(),
 463                         onchain_events_awaiting_threshold_conf: Vec::new(),
 464                         pending_claim_events: Vec::new(),
 465                         secp_ctx,
 466                 }
 467         }
 468
 469         pub(crate) fn get_prev_holder_commitment_to_self_value(&self) -> Option<u64> {
 470                 self.prev_holder_commitment.as_ref().map(|commitment| commitment.to_broadcaster_value_sat())
 471         }
 472
 473         pub(crate) fn get_cur_holder_commitment_to_self_value(&self) -> u64 {
 474                 self.holder_commitment.to_broadcaster_value_sat()
 475         }
 476
 477         pub(crate) fn get_and_clear_pending_claim_events(&mut self) -> Vec<(ClaimId, ClaimEvent)> {
 478                 let mut events = Vec::new();
 479                 swap(&mut events, &mut self.pending_claim_events);
 480                 events
 481         }
 482
 483         /// Triggers rebroadcasts/fee-bumps of pending claims from a force-closed channel. This is
 484         /// crucial in preventing certain classes of pinning attacks, detecting substantial mempool
 485         /// feerate changes between blocks, and ensuring reliability if broadcasting fails. We recommend
 486         /// invoking this every 30 seconds, or lower if running in an environment with spotty
 487         /// connections, like on mobile.
 488         pub(crate) fn rebroadcast_pending_claims<B: Deref, F: Deref, L: Deref>(
 489                 &mut self, current_height: u32, broadcaster: &B, fee_estimator: &LowerBoundedFeeEstimator<F>,
 490                 logger: &L,
 491         )
 492         where
 493                 B::Target: BroadcasterInterface,
 494                 F::Target: FeeEstimator,
 495                 L::Target: Logger,
 496         {
 497                 let mut bump_requests = Vec::with_capacity(self.pending_claim_requests.len());
 498                 for (claim_id, request) in self.pending_claim_requests.iter() {
 499                         let inputs = request.outpoints();
 500                         log_info!(logger, "Triggering rebroadcast/fee-bump for request with inputs {:?}", inputs);
 501                         bump_requests.push((*claim_id, request.clone()));
 502                 }
 503                 for (claim_id, request) in bump_requests {
 504                         self.generate_claim(current_height, &request, false /* force_feerate_bump */, fee_estimator, logger)
 505                                 .map(|(_, new_feerate, claim)| {
 506                                         let mut bumped_feerate = false;
 507                                         if let Some(mut_request) = self.pending_claim_requests.get_mut(&claim_id) {
 508                                                 bumped_feerate = request.previous_feerate() > new_feerate;
 509                                                 mut_request.set_feerate(new_feerate);
 510                                         }
 511                                         match claim {
 512                                                 OnchainClaim::Tx(tx) => {
 513                                                         let log_start = if bumped_feerate { "Broadcasting RBF-bumped" } else { "Rebroadcasting" };
 514                                                         log_info!(logger, "{} onchain {}", log_start, log_tx!(tx));
 515                                                         broadcaster.broadcast_transactions(&[&tx]);
 516                                                 },
 517                                                 OnchainClaim::Event(event) => {
 518                                                         let log_start = if bumped_feerate { "Yielding fee-bumped" } else { "Replaying" };
 519                                                         log_info!(logger, "{} onchain event to spend inputs {:?}", log_start,
 520                                                                 request.outpoints());
 521                                                         #[cfg(debug_assertions)] {
 522                                                                 debug_assert!(request.requires_external_funding());
 523                                                                 let num_existing = self.pending_claim_events.iter()
 524                                                                         .filter(|entry| entry.0 == claim_id).count();
 525                                                                 assert!(num_existing == 0 || num_existing == 1);
 526                                                         }
 527                                                         self.pending_claim_events.retain(|event| event.0 != claim_id);
 528                                                         self.pending_claim_events.push((claim_id, event));
 529                                                 }
 530                                         }
 531                                 });
 532                 }
 533         }
 534
 535         /// Lightning security model (i.e being able to redeem/timeout HTLC or penalize counterparty
 536         /// onchain) lays on the assumption of claim transactions getting confirmed before timelock
 537         /// expiration (CSV or CLTV following cases). In case of high-fee spikes, claim tx may get stuck
 538         /// in the mempool, so you need to bump its feerate quickly using Replace-By-Fee or
 539         /// Child-Pay-For-Parent.
 540         ///
 541         /// Panics if there are signing errors, because signing operations in reaction to on-chain
 542         /// events are not expected to fail, and if they do, we may lose funds.
 543         fn generate_claim<F: Deref, L: Deref>(
 544                 &mut self, cur_height: u32, cached_request: &PackageTemplate, force_feerate_bump: bool,
 545                 fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L,
 546         ) -> Option<(u32, u64, OnchainClaim)>
 547         where
 548                 F::Target: FeeEstimator,
 549                 L::Target: Logger,
 550         {
 551                 let request_outpoints = cached_request.outpoints();
 552                 if request_outpoints.is_empty() {
 553                         // Don't prune pending claiming request yet, we may have to resurrect HTLCs. Untractable
 554                         // packages cannot be aggregated and will never be split, so we cannot end up with an
 555                         // empty claim.
 556                         debug_assert!(cached_request.is_malleable());
 557                         return None;
 558                 }
 559                 // If we've seen transaction inclusion in the chain for all outpoints in our request, we
 560                 // don't need to continue generating more claims. We'll keep tracking the request to fully
 561                 // remove it once it reaches the confirmation threshold, or to generate a new claim if the
 562                 // transaction is reorged out.
 563                 let mut all_inputs_have_confirmed_spend = true;
 564                 for outpoint in request_outpoints.iter() {
 565                         if let Some((request_claim_id, _)) = self.claimable_outpoints.get(*outpoint) {
 566                                 // We check for outpoint spends within claims individually rather than as a set
 567                                 // since requests can have outpoints split off.
 568                                 if !self.onchain_events_awaiting_threshold_conf.iter()
 569                                         .any(|event_entry| if let OnchainEvent::Claim { claim_id } = event_entry.event {
 570                                                 *request_claim_id == claim_id
 571                                         } else {
 572                                                 // The onchain event is not a claim, keep seeking until we find one.
 573                                                 false
 574                                         })
 575                                 {
 576                                         // Either we had no `OnchainEvent::Claim`, or we did but none matched the
 577                                         // outpoint's registered spend.
 578                                         all_inputs_have_confirmed_spend = false;
 579                                 }
 580                         } else {
 581                                 // The request's outpoint spend does not exist yet.
 582                                 all_inputs_have_confirmed_spend = false;
 583                         }
 584                 }
 585                 if all_inputs_have_confirmed_spend {
 586                         return None;
 587                 }
 588
 589                 // Compute new height timer to decide when we need to regenerate a new bumped version of the claim tx (if we
 590                 // didn't receive confirmation of it before, or not enough reorg-safe depth on top of it).
 591                 let new_timer = cached_request.get_height_timer(cur_height);
 592                 if cached_request.is_malleable() {
 593                         if cached_request.requires_external_funding() {
 594                                 let target_feerate_sat_per_1000_weight = cached_request.compute_package_feerate(
 595                                         fee_estimator, ConfirmationTarget::HighPriority, force_feerate_bump
 596                                 );
 597                                 if let Some(htlcs) = cached_request.construct_malleable_package_with_external_funding(self) {
 598                                         return Some((
 599                                                 new_timer,
 600                                                 target_feerate_sat_per_1000_weight as u64,
 601                                                 OnchainClaim::Event(ClaimEvent::BumpHTLC {
 602                                                         target_feerate_sat_per_1000_weight,
 603                                                         htlcs,
 604                                                         tx_lock_time: PackedLockTime(cached_request.package_locktime(cur_height)),
 605                                                 }),
 606                                         ));
 607                                 } else {
 608                                         return None;
 609                                 }
 610                         }
 611
 612                         let predicted_weight = cached_request.package_weight(&self.destination_script);
 613                         if let Some((output_value, new_feerate)) = cached_request.compute_package_output(
 614                                 predicted_weight, self.destination_script.dust_value().to_sat(),
 615                                 force_feerate_bump, fee_estimator, logger,
 616                         ) {
 617                                 assert!(new_feerate != 0);
 618
 619                                 let transaction = cached_request.finalize_malleable_package(
 620                                         cur_height, self, output_value, self.destination_script.clone(), logger
 621                                 ).unwrap();
 622                                 log_trace!(logger, "...with timer {} and feerate {}", new_timer, new_feerate);
 623                                 assert!(predicted_weight >= transaction.weight());
 624                                 return Some((new_timer, new_feerate, OnchainClaim::Tx(transaction)));
 625                         }
 626                 } else {
 627                         // Untractable packages cannot have their fees bumped through Replace-By-Fee. Some
 628                         // packages may support fee bumping through Child-Pays-For-Parent, indicated by those
 629                         // which require external funding.
 630                         let mut inputs = cached_request.inputs();
 631                         debug_assert_eq!(inputs.len(), 1);
 632                         let tx = match cached_request.finalize_untractable_package(self, logger) {
 633                                 Some(tx) => tx,
 634                                 None => return None,
 635                         };
 636                         if !cached_request.requires_external_funding() {
 637                                 return Some((new_timer, 0, OnchainClaim::Tx(tx)));
 638                         }
 639                         return inputs.find_map(|input| match input {
 640                                 // Commitment inputs with anchors support are the only untractable inputs supported
 641                                 // thus far that require external funding.
 642                                 PackageSolvingData::HolderFundingOutput(output) => {
 643                                         debug_assert_eq!(tx.txid(), self.holder_commitment.trust().txid(),
 644                                                 "Holder commitment transaction mismatch");
 645
 646                                         let conf_target = ConfirmationTarget::HighPriority;
 647                                         let package_target_feerate_sat_per_1000_weight = cached_request
 648                                                 .compute_package_feerate(fee_estimator, conf_target, force_feerate_bump);
 649                                         if let Some(input_amount_sat) = output.funding_amount {
 650                                                 let fee_sat = input_amount_sat - tx.output.iter().map(|output| output.value).sum::<u64>();
 651                                                 let commitment_tx_feerate_sat_per_1000_weight =
 652                                                         compute_feerate_sat_per_1000_weight(fee_sat, tx.weight() as u64);
 653                                                 if commitment_tx_feerate_sat_per_1000_weight >= package_target_feerate_sat_per_1000_weight {
 654                                                         log_debug!(logger, "Pre-signed {} already has feerate {} sat/kW above required {} sat/kW",
 655                                                                 log_tx!(tx), commitment_tx_feerate_sat_per_1000_weight,
 656                                                                 package_target_feerate_sat_per_1000_weight);
 657                                                         return Some((new_timer, 0, OnchainClaim::Tx(tx.clone())));
 658                                                 }
 659                                         }
 660
 661                                         // We'll locate an anchor output we can spend within the commitment transaction.
 662                                         let funding_pubkey = &self.channel_transaction_parameters.holder_pubkeys.funding_pubkey;
 663                                         match chan_utils::get_anchor_output(&tx, funding_pubkey) {
 664                                                 // An anchor output was found, so we should yield a funding event externally.
 665                                                 Some((idx, _)) => {
 666                                                         // TODO: Use a lower confirmation target when both our and the
 667                                                         // counterparty's latest commitment don't have any HTLCs present.
 668                                                         Some((
 669                                                                 new_timer,
 670                                                                 package_target_feerate_sat_per_1000_weight as u64,
 671                                                                 OnchainClaim::Event(ClaimEvent::BumpCommitment {
 672                                                                         package_target_feerate_sat_per_1000_weight,
 673                                                                         commitment_tx: tx.clone(),
 674                                                                         anchor_output_idx: idx,
 675                                                                 }),
 676                                                         ))
 677                                                 },
 678                                                 // An anchor output was not found. There's nothing we can do other than
 679                                                 // attempt to broadcast the transaction with its current fee rate and hope
 680                                                 // it confirms. This is essentially the same behavior as a commitment
 681                                                 // transaction without anchor outputs.
 682                                                 None => Some((new_timer, 0, OnchainClaim::Tx(tx.clone()))),
 683                                         }
 684                                 },
 685                                 _ => {
 686                                         debug_assert!(false, "Only HolderFundingOutput inputs should be untractable and require external funding");
 687                                         None
 688                                 },
 689                         })
 690                 }
 691                 None
 692         }
 693
 694         /// Upon channelmonitor.block_connected(..) or upon provision of a preimage on the forward link
 695         /// for this channel, provide new relevant on-chain transactions and/or new claim requests.
 696         /// Together with `update_claims_view_from_matched_txn` this used to be named
 697         /// `block_connected`, but it is now also used for claiming an HTLC output if we receive a
 698         /// preimage after force-close.
 699         ///
 700         /// `conf_height` represents the height at which the request was generated. This
 701         /// does not need to equal the current blockchain tip height, which should be provided via
 702         /// `cur_height`, however it must never be higher than `cur_height`.
 703         pub(crate) fn update_claims_view_from_requests<B: Deref, F: Deref, L: Deref>(
 704                 &mut self, requests: Vec<PackageTemplate>, conf_height: u32, cur_height: u32,
 705                 broadcaster: &B, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L
 706         ) where
 707                 B::Target: BroadcasterInterface,
 708                 F::Target: FeeEstimator,
 709                 L::Target: Logger,
 710         {
 711                 log_debug!(logger, "Updating claims view at height {} with {} claim requests", cur_height, requests.len());
 712                 let mut preprocessed_requests = Vec::with_capacity(requests.len());
 713                 let mut aggregated_request = None;
 714
 715                 // Try to aggregate outputs if their timelock expiration isn't imminent (package timelock
 716                 // <= CLTV_SHARED_CLAIM_BUFFER) and they don't require an immediate nLockTime (aggregable).
 717                 for req in requests {
 718                         // Don't claim a outpoint twice that would be bad for privacy and may uselessly lock a CPFP input for a while
 719                         if let Some(_) = self.claimable_outpoints.get(req.outpoints()[0]) {
 720                                 log_info!(logger, "Ignoring second claim for outpoint {}:{}, already registered its claiming request", req.outpoints()[0].txid, req.outpoints()[0].vout);
 721                         } else {
 722                                 let timelocked_equivalent_package = self.locktimed_packages.iter().map(|v| v.1.iter()).flatten()
 723                                         .find(|locked_package| locked_package.outpoints() == req.outpoints());
 724                                 if let Some(package) = timelocked_equivalent_package {
 725                                         log_info!(logger, "Ignoring second claim for outpoint {}:{}, we already have one which we're waiting on a timelock at {} for.",
 726                                                 req.outpoints()[0].txid, req.outpoints()[0].vout, package.package_locktime(cur_height));
 727                                         continue;
 728                                 }
 729
 730                                 let package_locktime = req.package_locktime(cur_height);
 731                                 if package_locktime > cur_height + 1 {
 732                                         log_info!(logger, "Delaying claim of package until its timelock at {} (current height {}), the following outpoints are spent:", package_locktime, cur_height);
 733                                         for outpoint in req.outpoints() {
 734                                                 log_info!(logger, "  Outpoint {}", outpoint);
 735                                         }
 736                                         self.locktimed_packages.entry(package_locktime).or_insert(Vec::new()).push(req);
 737                                         continue;
 738                                 }
 739
 740                                 log_trace!(logger, "Test if outpoint can be aggregated with expiration {} against {}", req.timelock(), cur_height + CLTV_SHARED_CLAIM_BUFFER);
 741                                 if req.timelock() <= cur_height + CLTV_SHARED_CLAIM_BUFFER || !req.aggregable() {
 742                                         // Don't aggregate if outpoint package timelock is soon or marked as non-aggregable
 743                                         preprocessed_requests.push(req);
 744                                 } else if aggregated_request.is_none() {
 745                                         aggregated_request = Some(req);
 746                                 } else {
 747                                         aggregated_request.as_mut().unwrap().merge_package(req);
 748                                 }
 749                         }
 750                 }
 751                 if let Some(req) = aggregated_request {
 752                         preprocessed_requests.push(req);
 753                 }
 754
 755                 // Claim everything up to and including `cur_height`
 756                 let remaining_locked_packages = self.locktimed_packages.split_off(&(cur_height + 1));
 757                 for (pop_height, mut entry) in self.locktimed_packages.iter_mut() {
 758                         log_trace!(logger, "Restoring delayed claim of package(s) at their timelock at {}.", pop_height);
 759                         preprocessed_requests.append(&mut entry);
 760                 }
 761                 self.locktimed_packages = remaining_locked_packages;
 762
 763                 // Generate claim transactions and track them to bump if necessary at
 764                 // height timer expiration (i.e in how many blocks we're going to take action).
 765                 for mut req in preprocessed_requests {
 766                         if let Some((new_timer, new_feerate, claim)) = self.generate_claim(
 767                                 cur_height, &req, true /* force_feerate_bump */, &*fee_estimator, &*logger,
 768                         ) {
 769                                 req.set_timer(new_timer);
 770                                 req.set_feerate(new_feerate);
 771                                 // Once a pending claim has an id assigned, it remains fixed until the claim is
 772                                 // satisfied, regardless of whether the claim switches between different variants of
 773                                 // `OnchainClaim`.
 774                                 let claim_id = match claim {
 775                                         OnchainClaim::Tx(tx) => {
 776                                                 log_info!(logger, "Broadcasting onchain {}", log_tx!(tx));
 777                                                 broadcaster.broadcast_transactions(&[&tx]);
 778                                                 ClaimId(tx.txid().into_inner())
 779                                         },
 780                                         OnchainClaim::Event(claim_event) => {
 781                                                 log_info!(logger, "Yielding onchain event to spend inputs {:?}", req.outpoints());
 782                                                 let claim_id = match claim_event {
 783                                                         ClaimEvent::BumpCommitment { ref commitment_tx, .. } =>
 784                                                                 // For commitment claims, we can just use their txid as it should
 785                                                                 // already be unique.
 786                                                                 ClaimId(commitment_tx.txid().into_inner()),
 787                                                         ClaimEvent::BumpHTLC { ref htlcs, .. } => {
 788                                                                 // For HTLC claims, commit to the entire set of HTLC outputs to
 789                                                                 // claim, which will always be unique per request. Once a claim ID
 790                                                                 // is generated, it is assigned and remains unchanged, even if the
 791                                                                 // underlying set of HTLCs changes.
 792                                                                 let mut engine = Sha256::engine();
 793                                                                 for htlc in htlcs {
 794                                                                         engine.input(&htlc.commitment_txid.into_inner());
 795                                                                         engine.input(&htlc.htlc.transaction_output_index.unwrap().to_be_bytes());
 796                                                                 }
 797                                                                 ClaimId(Sha256::from_engine(engine).into_inner())
 798                                                         },
 799                                                 };
 800                                                 debug_assert!(self.pending_claim_requests.get(&claim_id).is_none());
 801                                                 debug_assert_eq!(self.pending_claim_events.iter().filter(|entry| entry.0 == claim_id).count(), 0);
 802                                                 self.pending_claim_events.push((claim_id, claim_event));
 803                                                 claim_id
 804                                         },
 805                                 };
 806                                 debug_assert!(self.pending_claim_requests.get(&claim_id).is_none());
 807                                 for k in req.outpoints() {
 808                                         log_info!(logger, "Registering claiming request for {}:{}", k.txid, k.vout);
 809                                         self.claimable_outpoints.insert(k.clone(), (claim_id, conf_height));
 810                                 }
 811                                 self.pending_claim_requests.insert(claim_id, req);
 812                         }
 813                 }
 814         }
 815
 816         /// Upon channelmonitor.block_connected(..) or upon provision of a preimage on the forward link
 817         /// for this channel, provide new relevant on-chain transactions and/or new claim requests.
 818         /// Together with `update_claims_view_from_requests` this used to be named `block_connected`,
 819         /// but it is now also used for claiming an HTLC output if we receive a preimage after force-close.
 820         ///
 821         /// `conf_height` represents the height at which the transactions in `txn_matched` were
 822         /// confirmed. This does not need to equal the current blockchain tip height, which should be
 823         /// provided via `cur_height`, however it must never be higher than `cur_height`.
 824         pub(crate) fn update_claims_view_from_matched_txn<B: Deref, F: Deref, L: Deref>(
 825                 &mut self, txn_matched: &[&Transaction], conf_height: u32, conf_hash: BlockHash,
 826                 cur_height: u32, broadcaster: &B, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L
 827         ) where
 828                 B::Target: BroadcasterInterface,
 829                 F::Target: FeeEstimator,
 830                 L::Target: Logger,
 831         {
 832                 log_debug!(logger, "Updating claims view at height {} with {} matched transactions in block {}", cur_height, txn_matched.len(), conf_height);
 833                 let mut bump_candidates = HashMap::new();
 834                 for tx in txn_matched {
 835                         // Scan all input to verify is one of the outpoint spent is of interest for us
 836                         let mut claimed_outputs_material = Vec::new();
 837                         for inp in &tx.input {
 838                                 if let Some((claim_id, _)) = self.claimable_outpoints.get(&inp.previous_output) {
 839                                         // If outpoint has claim request pending on it...
 840                                         if let Some(request) = self.pending_claim_requests.get_mut(claim_id) {
 841                                                 //... we need to verify equality between transaction outpoints and claim request
 842                                                 // outpoints to know if transaction is the original claim or a bumped one issued
 843                                                 // by us.
 844                                                 let mut are_sets_equal = true;
 845                                                 let mut tx_inputs = tx.input.iter().map(|input| &input.previous_output).collect::<Vec<_>>();
 846                                                 tx_inputs.sort_unstable();
 847                                                 for request_input in request.outpoints() {
 848                                                         if tx_inputs.binary_search(&request_input).is_err() {
 849                                                                 are_sets_equal = false;
 850                                                                 break;
 851                                                         }
 852                                                 }
 853
 854                                                 macro_rules! clean_claim_request_after_safety_delay {
 855                                                         () => {
 856                                                                 let entry = OnchainEventEntry {
 857                                                                         txid: tx.txid(),
 858                                                                         height: conf_height,
 859                                                                         block_hash: Some(conf_hash),
 860                                                                         event: OnchainEvent::Claim { claim_id: *claim_id }
 861                                                                 };
 862                                                                 if !self.onchain_events_awaiting_threshold_conf.contains(&entry) {
 863                                                                         self.onchain_events_awaiting_threshold_conf.push(entry);
 864                                                                 }
 865                                                         }
 866                                                 }
 867
 868                                                 // If this is our transaction (or our counterparty spent all the outputs
 869                                                 // before we could anyway with same inputs order than us), wait for
 870                                                 // ANTI_REORG_DELAY and clean the RBF tracking map.
 871                                                 if are_sets_equal {
 872                                                         clean_claim_request_after_safety_delay!();
 873                                                 } else { // If false, generate new claim request with update outpoint set
 874                                                         let mut at_least_one_drop = false;
 875                                                         for input in tx.input.iter() {
 876                                                                 if let Some(package) = request.split_package(&input.previous_output) {
 877                                                                         claimed_outputs_material.push(package);
 878                                                                         at_least_one_drop = true;
 879                                                                 }
 880                                                                 // If there are no outpoints left to claim in this request, drop it entirely after ANTI_REORG_DELAY.
 881                                                                 if request.outpoints().is_empty() {
 882                                                                         clean_claim_request_after_safety_delay!();
 883                                                                 }
 884                                                         }
 885                                                         //TODO: recompute soonest_timelock to avoid wasting a bit on fees
 886                                                         if at_least_one_drop {
 887                                                                 bump_candidates.insert(*claim_id, request.clone());
 888                                                                 // If we have any pending claim events for the request being updated
 889                                                                 // that have yet to be consumed, we'll remove them since they will
 890                                                                 // end up producing an invalid transaction by double spending
 891                                                                 // input(s) that already have a confirmed spend. If such spend is
 892                                                                 // reorged out of the chain, then we'll attempt to re-spend the
 893                                                                 // inputs once we see it.
 894                                                                 #[cfg(debug_assertions)] {
 895                                                                         let existing = self.pending_claim_events.iter()
 896                                                                                 .filter(|entry| entry.0 == *claim_id).count();
 897                                                                         assert!(existing == 0 || existing == 1);
 898                                                                 }
 899                                                                 self.pending_claim_events.retain(|entry| entry.0 != *claim_id);
 900                                                         }
 901                                                 }
 902                                                 break; //No need to iterate further, either tx is our or their
 903                                         } else {
 904                                                 panic!("Inconsistencies between pending_claim_requests map and claimable_outpoints map");
 905                                         }
 906                                 }
 907                         }
 908                         for package in claimed_outputs_material.drain(..) {
 909                                 let entry = OnchainEventEntry {
 910                                         txid: tx.txid(),
 911                                         height: conf_height,
 912                                         block_hash: Some(conf_hash),
 913                                         event: OnchainEvent::ContentiousOutpoint { package },
 914                                 };
 915                                 if !self.onchain_events_awaiting_threshold_conf.contains(&entry) {
 916                                         self.onchain_events_awaiting_threshold_conf.push(entry);
 917                                 }
 918                         }
 919                 }
 920
 921                 // After security delay, either our claim tx got enough confs or outpoint is definetely out of reach
 922                 let onchain_events_awaiting_threshold_conf =
 923                         self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
 924                 for entry in onchain_events_awaiting_threshold_conf {
 925                         if entry.has_reached_confirmation_threshold(cur_height) {
 926                                 match entry.event {
 927                                         OnchainEvent::Claim { claim_id } => {
 928                                                 // We may remove a whole set of claim outpoints here, as these one may have
 929                                                 // been aggregated in a single tx and claimed so atomically
 930                                                 if let Some(request) = self.pending_claim_requests.remove(&claim_id) {
 931                                                         for outpoint in request.outpoints() {
 932                                                                 log_debug!(logger, "Removing claim tracking for {} due to maturation of claim package {}.",
 933                                                                         outpoint, log_bytes!(claim_id.0));
 934                                                                 self.claimable_outpoints.remove(outpoint);
 935                                                         }
 936                                                         #[cfg(debug_assertions)] {
 937                                                                 let num_existing = self.pending_claim_events.iter()
 938                                                                         .filter(|entry| entry.0 == claim_id).count();
 939                                                                 assert!(num_existing == 0 || num_existing == 1);
 940                                                         }
 941                                                         self.pending_claim_events.retain(|(id, _)| *id != claim_id);
 942                                                 }
 943                                         },
 944                                         OnchainEvent::ContentiousOutpoint { package } => {
 945                                                 log_debug!(logger, "Removing claim tracking due to maturation of claim tx for outpoints:");
 946                                                 log_debug!(logger, " {:?}", package.outpoints());
 947                                                 self.claimable_outpoints.remove(package.outpoints()[0]);
 948                                         }
 949                                 }
 950                         } else {
 951                                 self.onchain_events_awaiting_threshold_conf.push(entry);
 952                         }
 953                 }
 954
 955                 // Check if any pending claim request must be rescheduled
 956                 for (claim_id, request) in self.pending_claim_requests.iter() {
 957                         if cur_height >= request.timer() {
 958                                 bump_candidates.insert(*claim_id, request.clone());
 959                         }
 960                 }
 961
 962                 // Build, bump and rebroadcast tx accordingly
 963                 log_trace!(logger, "Bumping {} candidates", bump_candidates.len());
 964                 for (claim_id, request) in bump_candidates.iter() {
 965                         if let Some((new_timer, new_feerate, bump_claim)) = self.generate_claim(
 966                                 cur_height, &request, true /* force_feerate_bump */, &*fee_estimator, &*logger,
 967                         ) {
 968                                 match bump_claim {
 969                                         OnchainClaim::Tx(bump_tx) => {
 970                                                 log_info!(logger, "Broadcasting RBF-bumped onchain {}", log_tx!(bump_tx));
 971                                                 broadcaster.broadcast_transactions(&[&bump_tx]);
 972                                         },
 973                                         OnchainClaim::Event(claim_event) => {
 974                                                 log_info!(logger, "Yielding RBF-bumped onchain event to spend inputs {:?}", request.outpoints());
 975                                                 #[cfg(debug_assertions)] {
 976                                                         let num_existing = self.pending_claim_events.iter().
 977                                                                 filter(|entry| entry.0 == *claim_id).count();
 978                                                         assert!(num_existing == 0 || num_existing == 1);
 979                                                 }
 980                                                 self.pending_claim_events.retain(|event| event.0 != *claim_id);
 981                                                 self.pending_claim_events.push((*claim_id, claim_event));
 982                                         },
 983                                 }
 984                                 if let Some(request) = self.pending_claim_requests.get_mut(claim_id) {
 985                                         request.set_timer(new_timer);
 986                                         request.set_feerate(new_feerate);
 987                                 }
 988                         }
 989                 }
 990         }
 991
 992         pub(crate) fn transaction_unconfirmed<B: Deref, F: Deref, L: Deref>(
 993                 &mut self,
 994                 txid: &Txid,
 995                 broadcaster: B,
 996                 fee_estimator: &LowerBoundedFeeEstimator<F>,
 997                 logger: L,
 998         ) where
 999                 B::Target: BroadcasterInterface,
1000                 F::Target: FeeEstimator,
1001                 L::Target: Logger,
1002         {
1003                 let mut height = None;
1004                 for entry in self.onchain_events_awaiting_threshold_conf.iter() {
1005                         if entry.txid == *txid {
1006                                 height = Some(entry.height);
1007                                 break;
1008                         }
1009                 }
1010
1011                 if let Some(height) = height {
1012                         self.block_disconnected(height, broadcaster, fee_estimator, logger);
1013                 }
1014         }
1015
1016         pub(crate) fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, height: u32, broadcaster: B, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: L)
1017                 where B::Target: BroadcasterInterface,
1018                       F::Target: FeeEstimator,
1019                                         L::Target: Logger,
1020         {
1021                 let mut bump_candidates = HashMap::new();
1022                 let onchain_events_awaiting_threshold_conf =
1023                         self.onchain_events_awaiting_threshold_conf.drain(..).collect::<Vec<_>>();
1024                 for entry in onchain_events_awaiting_threshold_conf {
1025                         if entry.height >= height {
1026                                 //- our claim tx on a commitment tx output
1027                                 //- resurect outpoint back in its claimable set and regenerate tx
1028                                 match entry.event {
1029                                         OnchainEvent::ContentiousOutpoint { package } => {
1030                                                 if let Some(pending_claim) = self.claimable_outpoints.get(package.outpoints()[0]) {
1031                                                         if let Some(request) = self.pending_claim_requests.get_mut(&pending_claim.0) {
1032                                                                 request.merge_package(package);
1033                                                                 // Using a HashMap guarantee us than if we have multiple outpoints getting
1034                                                                 // resurrected only one bump claim tx is going to be broadcast
1035                                                                 bump_candidates.insert(pending_claim.clone(), request.clone());
1036                                                         }
1037                                                 }
1038                                         },
1039                                         _ => {},
1040                                 }
1041                         } else {
1042                                 self.onchain_events_awaiting_threshold_conf.push(entry);
1043                         }
1044                 }
1045                 for ((_claim_id, _), ref mut request) in bump_candidates.iter_mut() {
1046                         // `height` is the height being disconnected, so our `current_height` is 1 lower.
1047                         let current_height = height - 1;
1048                         if let Some((new_timer, new_feerate, bump_claim)) = self.generate_claim(
1049                                 current_height, &request, true /* force_feerate_bump */, fee_estimator, &&*logger
1050                         ) {
1051                                 request.set_timer(new_timer);
1052                                 request.set_feerate(new_feerate);
1053                                 match bump_claim {
1054                                         OnchainClaim::Tx(bump_tx) => {
1055                                                 log_info!(logger, "Broadcasting onchain {}", log_tx!(bump_tx));
1056                                                 broadcaster.broadcast_transactions(&[&bump_tx]);
1057                                         },
1058                                         OnchainClaim::Event(claim_event) => {
1059                                                 log_info!(logger, "Yielding onchain event after reorg to spend inputs {:?}", request.outpoints());
1060                                                 #[cfg(debug_assertions)] {
1061                                                         let num_existing = self.pending_claim_events.iter()
1062                                                                 .filter(|entry| entry.0 == *_claim_id).count();
1063                                                         assert!(num_existing == 0 || num_existing == 1);
1064                                                 }
1065                                                 self.pending_claim_events.retain(|event| event.0 != *_claim_id);
1066                                                 self.pending_claim_events.push((*_claim_id, claim_event));
1067                                         },
1068                                 }
1069                         }
1070                 }
1071                 for (ancestor_claim_txid, request) in bump_candidates.drain() {
1072                         self.pending_claim_requests.insert(ancestor_claim_txid.0, request);
1073                 }
1074                 //TODO: if we implement cross-block aggregated claim transaction we need to refresh set of outpoints and regenerate tx but
1075                 // right now if one of the outpoint get disconnected, just erase whole pending claim request.
1076                 let mut remove_request = Vec::new();
1077                 self.claimable_outpoints.retain(|_, ref v|
1078                         if v.1 >= height {
1079                         remove_request.push(v.0.clone());
1080                         false
1081                         } else { true });
1082                 for req in remove_request {
1083                         self.pending_claim_requests.remove(&req);
1084                 }
1085         }
1086
1087         pub(crate) fn is_output_spend_pending(&self, outpoint: &BitcoinOutPoint) -> bool {
1088                 self.claimable_outpoints.get(outpoint).is_some()
1089         }
1090
1091         pub(crate) fn get_relevant_txids(&self) -> Vec<(Txid, Option<BlockHash>)> {
1092                 let mut txids: Vec<(Txid, Option<BlockHash>)> = self.onchain_events_awaiting_threshold_conf
1093                         .iter()
1094                         .map(|entry| (entry.txid, entry.block_hash))
1095                         .collect();
1096                 txids.sort_unstable_by_key(|(txid, _)| *txid);
1097                 txids.dedup();
1098                 txids
1099         }
1100
1101         pub(crate) fn provide_latest_holder_tx(&mut self, tx: HolderCommitmentTransaction) {
1102                 self.prev_holder_commitment = Some(replace(&mut self.holder_commitment, tx));
1103                 self.holder_htlc_sigs = None;
1104         }
1105
1106         // Normally holder HTLCs are signed at the same time as the holder commitment tx.  However,
1107         // in some configurations, the holder commitment tx has been signed and broadcast by a
1108         // ChannelMonitor replica, so we handle that case here.
1109         fn sign_latest_holder_htlcs(&mut self) {
1110                 if self.holder_htlc_sigs.is_none() {
1111                         let (_sig, sigs) = self.signer.sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("sign holder commitment");
1112                         self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, sigs));
1113                 }
1114         }
1115
1116         // Normally only the latest commitment tx and HTLCs need to be signed.  However, in some
1117         // configurations we may have updated our holder commitment but a replica of the ChannelMonitor
1118         // broadcast the previous one before we sync with it.  We handle that case here.
1119         fn sign_prev_holder_htlcs(&mut self) {
1120                 if self.prev_holder_htlc_sigs.is_none() {
1121                         if let Some(ref holder_commitment) = self.prev_holder_commitment {
1122                                 let (_sig, sigs) = self.signer.sign_holder_commitment_and_htlcs(holder_commitment, &self.secp_ctx).expect("sign previous holder commitment");
1123                                 self.prev_holder_htlc_sigs = Some(Self::extract_holder_sigs(holder_commitment, sigs));
1124                         }
1125                 }
1126         }
1127
1128         fn extract_holder_sigs(holder_commitment: &HolderCommitmentTransaction, sigs: Vec<Signature>) -> Vec<Option<(usize, Signature)>> {
1129                 let mut ret = Vec::new();
1130                 for (htlc_idx, (holder_sig, htlc)) in sigs.iter().zip(holder_commitment.htlcs().iter()).enumerate() {
1131                         let tx_idx = htlc.transaction_output_index.unwrap();
1132                         if ret.len() <= tx_idx as usize { ret.resize(tx_idx as usize + 1, None); }
1133                         ret[tx_idx as usize] = Some((htlc_idx, holder_sig.clone()));
1134                 }
1135                 ret
1136         }
1137
1138         pub(crate) fn get_unsigned_holder_commitment_tx(&self) -> &Transaction {
1139                 &self.holder_commitment.trust().built_transaction().transaction
1140         }
1141
1142         //TODO: getting lastest holder transactions should be infallible and result in us "force-closing the channel", but we may
1143         // have empty holder commitment transaction if a ChannelMonitor is asked to force-close just after OutboundV1Channel::get_funding_created,
1144         // before providing a initial commitment transaction. For outbound channel, init ChannelMonitor at Channel::funding_signed, there is nothing
1145         // to monitor before.
1146         pub(crate) fn get_fully_signed_holder_tx(&mut self, funding_redeemscript: &Script) -> Transaction {
1147                 let (sig, htlc_sigs) = self.signer.sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("signing holder commitment");
1148                 self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, htlc_sigs));
1149                 self.holder_commitment.add_holder_sig(funding_redeemscript, sig)
1150         }
1151
1152         #[cfg(any(test, feature="unsafe_revoked_tx_signing"))]
1153         pub(crate) fn get_fully_signed_copy_holder_tx(&mut self, funding_redeemscript: &Script) -> Transaction {
1154                 let (sig, htlc_sigs) = self.signer.unsafe_sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("sign holder commitment");
1155                 self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, htlc_sigs));
1156                 self.holder_commitment.add_holder_sig(funding_redeemscript, sig)
1157         }
1158
1159         pub(crate) fn get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
1160                 let mut htlc_tx = None;
1161                 let commitment_txid = self.holder_commitment.trust().txid();
1162                 // Check if the HTLC spends from the current holder commitment
1163                 if commitment_txid == outp.txid {
1164                         self.sign_latest_holder_htlcs();
1165                         if let &Some(ref htlc_sigs) = &self.holder_htlc_sigs {
1166                                 let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
1167                                 let trusted_tx = self.holder_commitment.trust();
1168                                 let counterparty_htlc_sig = self.holder_commitment.counterparty_htlc_sigs[*htlc_idx];
1169                                 htlc_tx = Some(trusted_tx
1170                                         .get_signed_htlc_tx(&self.channel_transaction_parameters.as_holder_broadcastable(), *htlc_idx, &counterparty_htlc_sig, htlc_sig, preimage));
1171                         }
1172                 }
1173                 // If the HTLC doesn't spend the current holder commitment, check if it spends the previous one
1174                 if htlc_tx.is_none() && self.prev_holder_commitment.is_some() {
1175                         let commitment_txid = self.prev_holder_commitment.as_ref().unwrap().trust().txid();
1176                         if commitment_txid == outp.txid {
1177                                 self.sign_prev_holder_htlcs();
1178                                 if let &Some(ref htlc_sigs) = &self.prev_holder_htlc_sigs {
1179                                         let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
1180                                         let holder_commitment = self.prev_holder_commitment.as_ref().unwrap();
1181                                         let trusted_tx = holder_commitment.trust();
1182                                         let counterparty_htlc_sig = holder_commitment.counterparty_htlc_sigs[*htlc_idx];
1183                                         htlc_tx = Some(trusted_tx
1184                                                 .get_signed_htlc_tx(&self.channel_transaction_parameters.as_holder_broadcastable(), *htlc_idx, &counterparty_htlc_sig, htlc_sig, preimage));
1185                                 }
1186                         }
1187                 }
1188                 htlc_tx
1189         }
1190
1191         pub(crate) fn generate_external_htlc_claim(
1192                 &self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>
1193         ) -> Option<ExternalHTLCClaim> {
1194                 let find_htlc = |holder_commitment: &HolderCommitmentTransaction| -> Option<ExternalHTLCClaim> {
1195                         let trusted_tx = holder_commitment.trust();
1196                         if outp.txid != trusted_tx.txid() {
1197                                 return None;
1198                         }
1199                         trusted_tx.htlcs().iter().enumerate()
1200                                 .find(|(_, htlc)| if let Some(output_index) = htlc.transaction_output_index {
1201                                         output_index == outp.vout
1202                                 } else {
1203                                         false
1204                                 })
1205                                 .map(|(htlc_idx, htlc)| {
1206                                         let counterparty_htlc_sig = holder_commitment.counterparty_htlc_sigs[htlc_idx];
1207                                         ExternalHTLCClaim {
1208                                                 commitment_txid: trusted_tx.txid(),
1209                                                 per_commitment_number: trusted_tx.commitment_number(),
1210                                                 htlc: htlc.clone(),
1211                                                 preimage: *preimage,
1212                                                 counterparty_sig: counterparty_htlc_sig,
1213                                         }
1214                                 })
1215                 };
1216                 // Check if the HTLC spends from the current holder commitment or the previous one otherwise.
1217                 find_htlc(&self.holder_commitment)
1218                         .or_else(|| self.prev_holder_commitment.as_ref().map(|c| find_htlc(c)).flatten())
1219         }
1220
1221         pub(crate) fn channel_type_features(&self) -> &ChannelTypeFeatures {
1222                 &self.channel_transaction_parameters.channel_type_features
1223         }
1224
1225         #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
1226         pub(crate) fn unsafe_get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
1227                 let latest_had_sigs = self.holder_htlc_sigs.is_some();
1228                 let prev_had_sigs = self.prev_holder_htlc_sigs.is_some();
1229                 let ret = self.get_fully_signed_htlc_tx(outp, preimage);
1230                 if !latest_had_sigs {
1231                         self.holder_htlc_sigs = None;
1232                 }
1233                 if !prev_had_sigs {
1234                         self.prev_holder_htlc_sigs = None;
1235                 }
1236                 ret
1237         }
1238 }