_ Git - rust-lightning/blob - lightning/src/ln/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, TxIn, TxOut, SigHashType};
  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, Signature};
  22 use bitcoin::secp256k1;
  23
  24 use ln::msgs::DecodeError;
  25 use ln::channelmanager::PaymentPreimage;
  26 use ln::chan_utils;
  27 use ln::chan_utils::{TxCreationKeys, ChannelTransactionParameters, HolderCommitmentTransaction};
  28 use chain::chaininterface::{FeeEstimator, BroadcasterInterface, ConfirmationTarget, MIN_RELAY_FEE_SAT_PER_1000_WEIGHT};
  29 use chain::channelmonitor::{ANTI_REORG_DELAY, CLTV_SHARED_CLAIM_BUFFER, InputMaterial, ClaimRequest};
  30 use chain::keysinterface::{Sign, KeysInterface};
  31 use util::logger::Logger;
  32 use util::ser::{Readable, ReadableArgs, Writer, Writeable, VecWriter};
  33 use util::byte_utils;
  34
  35 use std::collections::{HashMap, hash_map};
  36 use std::cmp;
  37 use std::ops::Deref;
  38 use std::mem::replace;
  39
  40 const MAX_ALLOC_SIZE: usize = 64*1024;
  41
  42 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
  43 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
  44 #[derive(Clone, PartialEq)]
  45 enum OnchainEvent {
  46         /// Outpoint under claim process by our own tx, once this one get enough confirmations, we remove it from
  47         /// bump-txn candidate buffer.
  48         Claim {
  49                 claim_request: Txid,
  50         },
  51         /// Claim tx aggregate multiple claimable outpoints. One of the outpoint may be claimed by a counterparty party tx.
  52         /// In this case, we need to drop the outpoint and regenerate a new claim tx. By safety, we keep tracking
  53         /// the outpoint to be sure to resurect it back to the claim tx if reorgs happen.
  54         ContentiousOutpoint {
  55                 outpoint: BitcoinOutPoint,
  56                 input_material: InputMaterial,
  57         }
  58 }
  59
  60 /// Higher-level cache structure needed to re-generate bumped claim txn if needed
  61 #[derive(Clone, PartialEq)]
  62 pub struct ClaimTxBumpMaterial {
  63         // At every block tick, used to check if pending claiming tx is taking too
  64         // much time for confirmation and we need to bump it.
  65         height_timer: Option<u32>,
  66         // Tracked in case of reorg to wipe out now-superflous bump material
  67         feerate_previous: u32,
  68         // Soonest timelocks among set of outpoints claimed, used to compute
  69         // a priority of not feerate
  70         soonest_timelock: u32,
  71         // Cache of script, pubkey, sig or key to solve claimable outputs scriptpubkey.
  72         per_input_material: HashMap<BitcoinOutPoint, InputMaterial>,
  73 }
  74
  75 impl Writeable for ClaimTxBumpMaterial  {
  76         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
  77                 self.height_timer.write(writer)?;
  78                 writer.write_all(&byte_utils::be32_to_array(self.feerate_previous))?;
  79                 writer.write_all(&byte_utils::be32_to_array(self.soonest_timelock))?;
  80                 writer.write_all(&byte_utils::be64_to_array(self.per_input_material.len() as u64))?;
  81                 for (outp, tx_material) in self.per_input_material.iter() {
  82                         outp.write(writer)?;
  83                         tx_material.write(writer)?;
  84                 }
  85                 Ok(())
  86         }
  87 }
  88
  89 impl Readable for ClaimTxBumpMaterial {
  90         fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
  91                 let height_timer = Readable::read(reader)?;
  92                 let feerate_previous = Readable::read(reader)?;
  93                 let soonest_timelock = Readable::read(reader)?;
  94                 let per_input_material_len: u64 = Readable::read(reader)?;
  95                 let mut per_input_material = HashMap::with_capacity(cmp::min(per_input_material_len as usize, MAX_ALLOC_SIZE / 128));
  96                 for _ in 0 ..per_input_material_len {
  97                         let outpoint = Readable::read(reader)?;
  98                         let input_material = Readable::read(reader)?;
  99                         per_input_material.insert(outpoint, input_material);
 100                 }
 101                 Ok(Self { height_timer, feerate_previous, soonest_timelock, per_input_material })
 102         }
 103 }
 104
 105 #[derive(PartialEq, Clone, Copy)]
 106 pub(crate) enum InputDescriptors {
 107         RevokedOfferedHTLC,
 108         RevokedReceivedHTLC,
 109         OfferedHTLC,
 110         ReceivedHTLC,
 111         RevokedOutput, // either a revoked to_holder output on commitment tx, a revoked HTLC-Timeout output or a revoked HTLC-Success output
 112 }
 113
 114 impl Writeable for InputDescriptors {
 115         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 116                 match self {
 117                         &InputDescriptors::RevokedOfferedHTLC => {
 118                                 writer.write_all(&[0; 1])?;
 119                         },
 120                         &InputDescriptors::RevokedReceivedHTLC => {
 121                                 writer.write_all(&[1; 1])?;
 122                         },
 123                         &InputDescriptors::OfferedHTLC => {
 124                                 writer.write_all(&[2; 1])?;
 125                         },
 126                         &InputDescriptors::ReceivedHTLC => {
 127                                 writer.write_all(&[3; 1])?;
 128                         }
 129                         &InputDescriptors::RevokedOutput => {
 130                                 writer.write_all(&[4; 1])?;
 131                         }
 132                 }
 133                 Ok(())
 134         }
 135 }
 136
 137 impl Readable for InputDescriptors {
 138         fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
 139                 let input_descriptor = match <u8 as Readable>::read(reader)? {
 140                         0 => {
 141                                 InputDescriptors::RevokedOfferedHTLC
 142                         },
 143                         1 => {
 144                                 InputDescriptors::RevokedReceivedHTLC
 145                         },
 146                         2 => {
 147                                 InputDescriptors::OfferedHTLC
 148                         },
 149                         3 => {
 150                                 InputDescriptors::ReceivedHTLC
 151                         },
 152                         4 => {
 153                                 InputDescriptors::RevokedOutput
 154                         }
 155                         _ => return Err(DecodeError::InvalidValue),
 156                 };
 157                 Ok(input_descriptor)
 158         }
 159 }
 160
 161 macro_rules! subtract_high_prio_fee {
 162         ($logger: ident, $fee_estimator: expr, $value: expr, $predicted_weight: expr, $used_feerate: expr) => {
 163                 {
 164                         $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority).into();
 165                         let mut fee = $used_feerate as u64 * $predicted_weight / 1000;
 166                         if $value <= fee {
 167                                 $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Normal).into();
 168                                 fee = $used_feerate as u64 * $predicted_weight / 1000;
 169                                 if $value <= fee.into() {
 170                                         $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background).into();
 171                                         fee = $used_feerate as u64 * $predicted_weight / 1000;
 172                                         if $value <= fee {
 173                                                 log_error!($logger, "Failed to generate an on-chain punishment tx as even low priority fee ({} sat) was more than the entire claim balance ({} sat)",
 174                                                         fee, $value);
 175                                                 false
 176                                         } else {
 177                                                 log_warn!($logger, "Used low priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
 178                                                         $value);
 179                                                 $value -= fee;
 180                                                 true
 181                                         }
 182                                 } else {
 183                                         log_warn!($logger, "Used medium priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
 184                                                 $value);
 185                                         $value -= fee;
 186                                         true
 187                                 }
 188                         } else {
 189                                 $value -= fee;
 190                                 true
 191                         }
 192                 }
 193         }
 194 }
 195
 196 impl Readable for Option<Vec<Option<(usize, Signature)>>> {
 197         fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
 198                 match Readable::read(reader)? {
 199                         0u8 => Ok(None),
 200                         1u8 => {
 201                                 let vlen: u64 = Readable::read(reader)?;
 202                                 let mut ret = Vec::with_capacity(cmp::min(vlen as usize, MAX_ALLOC_SIZE / ::std::mem::size_of::<Option<(usize, Signature)>>()));
 203                                 for _ in 0..vlen {
 204                                         ret.push(match Readable::read(reader)? {
 205                                                 0u8 => None,
 206                                                 1u8 => Some((<u64 as Readable>::read(reader)? as usize, Readable::read(reader)?)),
 207                                                 _ => return Err(DecodeError::InvalidValue)
 208                                         });
 209                                 }
 210                                 Ok(Some(ret))
 211                         },
 212                         _ => Err(DecodeError::InvalidValue),
 213                 }
 214         }
 215 }
 216
 217 impl Writeable for Option<Vec<Option<(usize, Signature)>>> {
 218         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 219                 match self {
 220                         &Some(ref vec) => {
 221                                 1u8.write(writer)?;
 222                                 (vec.len() as u64).write(writer)?;
 223                                 for opt in vec.iter() {
 224                                         match opt {
 225                                                 &Some((ref idx, ref sig)) => {
 226                                                         1u8.write(writer)?;
 227                                                         (*idx as u64).write(writer)?;
 228                                                         sig.write(writer)?;
 229                                                 },
 230                                                 &None => 0u8.write(writer)?,
 231                                         }
 232                                 }
 233                         },
 234                         &None => 0u8.write(writer)?,
 235                 }
 236                 Ok(())
 237         }
 238 }
 239
 240
 241 /// OnchainTxHandler receives claiming requests, aggregates them if it's sound, broadcast and
 242 /// do RBF bumping if possible.
 243 pub struct OnchainTxHandler<ChannelSigner: Sign> {
 244         destination_script: Script,
 245         holder_commitment: HolderCommitmentTransaction,
 246         // holder_htlc_sigs and prev_holder_htlc_sigs are in the order as they appear in the commitment
 247         // transaction outputs (hence the Option<>s inside the Vec). The first usize is the index in
 248         // the set of HTLCs in the HolderCommitmentTransaction.
 249         holder_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
 250         prev_holder_commitment: Option<HolderCommitmentTransaction>,
 251         prev_holder_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
 252
 253         signer: ChannelSigner,
 254         pub(crate) channel_transaction_parameters: ChannelTransactionParameters,
 255
 256         // Used to track claiming requests. If claim tx doesn't confirm before height timer expiration we need to bump
 257         // it (RBF or CPFP). If an input has been part of an aggregate tx at first claim try, we need to keep it within
 258         // another bumped aggregate tx to comply with RBF rules. We may have multiple claiming txn in the flight for the
 259         // same set of outpoints. One of the outpoints may be spent by a transaction not issued by us. That's why at
 260         // block connection we scan all inputs and if any of them is among a set of a claiming request we test for set
 261         // equality between spending transaction and claim request. If true, it means transaction was one our claiming one
 262         // after a security delay of 6 blocks we remove pending claim request. If false, it means transaction wasn't and
 263         // we need to regenerate new claim request with reduced set of still-claimable outpoints.
 264         // Key is identifier of the pending claim request, i.e the txid of the initial claiming transaction generated by
 265         // us and is immutable until all outpoint of the claimable set are post-anti-reorg-delay solved.
 266         // Entry is cache of elements need to generate a bumped claiming transaction (see ClaimTxBumpMaterial)
 267         #[cfg(test)] // Used in functional_test to verify sanitization
 268         pub pending_claim_requests: HashMap<Txid, ClaimTxBumpMaterial>,
 269         #[cfg(not(test))]
 270         pending_claim_requests: HashMap<Txid, ClaimTxBumpMaterial>,
 271
 272         // Used to link outpoints claimed in a connected block to a pending claim request.
 273         // Key is outpoint than monitor parsing has detected we have keys/scripts to claim
 274         // Value is (pending claim request identifier, confirmation_block), identifier
 275         // is txid of the initial claiming transaction and is immutable until outpoint is
 276         // post-anti-reorg-delay solved, confirmaiton_block is used to erase entry if
 277         // block with output gets disconnected.
 278         #[cfg(test)] // Used in functional_test to verify sanitization
 279         pub claimable_outpoints: HashMap<BitcoinOutPoint, (Txid, u32)>,
 280         #[cfg(not(test))]
 281         claimable_outpoints: HashMap<BitcoinOutPoint, (Txid, u32)>,
 282
 283         onchain_events_waiting_threshold_conf: HashMap<u32, Vec<OnchainEvent>>,
 284
 285         latest_height: u32,
 286
 287         secp_ctx: Secp256k1<secp256k1::All>,
 288 }
 289
 290 impl<ChannelSigner: Sign> OnchainTxHandler<ChannelSigner> {
 291         pub(crate) fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 292                 self.destination_script.write(writer)?;
 293                 self.holder_commitment.write(writer)?;
 294                 self.holder_htlc_sigs.write(writer)?;
 295                 self.prev_holder_commitment.write(writer)?;
 296                 self.prev_holder_htlc_sigs.write(writer)?;
 297
 298                 self.channel_transaction_parameters.write(writer)?;
 299
 300                 let mut key_data = VecWriter(Vec::new());
 301                 self.signer.write(&mut key_data)?;
 302                 assert!(key_data.0.len() < std::usize::MAX);
 303                 assert!(key_data.0.len() < std::u32::MAX as usize);
 304                 (key_data.0.len() as u32).write(writer)?;
 305                 writer.write_all(&key_data.0[..])?;
 306
 307                 writer.write_all(&byte_utils::be64_to_array(self.pending_claim_requests.len() as u64))?;
 308                 for (ref ancestor_claim_txid, claim_tx_data) in self.pending_claim_requests.iter() {
 309                         ancestor_claim_txid.write(writer)?;
 310                         claim_tx_data.write(writer)?;
 311                 }
 312
 313                 writer.write_all(&byte_utils::be64_to_array(self.claimable_outpoints.len() as u64))?;
 314                 for (ref outp, ref claim_and_height) in self.claimable_outpoints.iter() {
 315                         outp.write(writer)?;
 316                         claim_and_height.0.write(writer)?;
 317                         claim_and_height.1.write(writer)?;
 318                 }
 319
 320                 writer.write_all(&byte_utils::be64_to_array(self.onchain_events_waiting_threshold_conf.len() as u64))?;
 321                 for (ref target, ref events) in self.onchain_events_waiting_threshold_conf.iter() {
 322                         writer.write_all(&byte_utils::be32_to_array(**target))?;
 323                         writer.write_all(&byte_utils::be64_to_array(events.len() as u64))?;
 324                         for ev in events.iter() {
 325                                 match *ev {
 326                                         OnchainEvent::Claim { ref claim_request } => {
 327                                                 writer.write_all(&[0; 1])?;
 328                                                 claim_request.write(writer)?;
 329                                         },
 330                                         OnchainEvent::ContentiousOutpoint { ref outpoint, ref input_material } => {
 331                                                 writer.write_all(&[1; 1])?;
 332                                                 outpoint.write(writer)?;
 333                                                 input_material.write(writer)?;
 334                                         }
 335                                 }
 336                         }
 337                 }
 338                 self.latest_height.write(writer)?;
 339                 Ok(())
 340         }
 341 }
 342
 343 impl<'a, K: KeysInterface> ReadableArgs<&'a K> for OnchainTxHandler<K::Signer> {
 344         fn read<R: ::std::io::Read>(reader: &mut R, keys_manager: &'a K) -> Result<Self, DecodeError> {
 345                 let destination_script = Readable::read(reader)?;
 346
 347                 let holder_commitment = Readable::read(reader)?;
 348                 let holder_htlc_sigs = Readable::read(reader)?;
 349                 let prev_holder_commitment = Readable::read(reader)?;
 350                 let prev_holder_htlc_sigs = Readable::read(reader)?;
 351
 352                 let channel_parameters = Readable::read(reader)?;
 353
 354                 let keys_len: u32 = Readable::read(reader)?;
 355                 let mut keys_data = Vec::with_capacity(cmp::min(keys_len as usize, MAX_ALLOC_SIZE));
 356                 while keys_data.len() != keys_len as usize {
 357                         // Read 1KB at a time to avoid accidentally allocating 4GB on corrupted channel keys
 358                         let mut data = [0; 1024];
 359                         let read_slice = &mut data[0..cmp::min(1024, keys_len as usize - keys_data.len())];
 360                         reader.read_exact(read_slice)?;
 361                         keys_data.extend_from_slice(read_slice);
 362                 }
 363                 let signer = keys_manager.read_chan_signer(&keys_data)?;
 364
 365                 let pending_claim_requests_len: u64 = Readable::read(reader)?;
 366                 let mut pending_claim_requests = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
 367                 for _ in 0..pending_claim_requests_len {
 368                         pending_claim_requests.insert(Readable::read(reader)?, Readable::read(reader)?);
 369                 }
 370
 371                 let claimable_outpoints_len: u64 = Readable::read(reader)?;
 372                 let mut claimable_outpoints = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
 373                 for _ in 0..claimable_outpoints_len {
 374                         let outpoint = Readable::read(reader)?;
 375                         let ancestor_claim_txid = Readable::read(reader)?;
 376                         let height = Readable::read(reader)?;
 377                         claimable_outpoints.insert(outpoint, (ancestor_claim_txid, height));
 378                 }
 379                 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
 380                 let mut onchain_events_waiting_threshold_conf = HashMap::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
 381                 for _ in 0..waiting_threshold_conf_len {
 382                         let height_target = Readable::read(reader)?;
 383                         let events_len: u64 = Readable::read(reader)?;
 384                         let mut events = Vec::with_capacity(cmp::min(events_len as usize, MAX_ALLOC_SIZE / 128));
 385                         for _ in 0..events_len {
 386                                 let ev = match <u8 as Readable>::read(reader)? {
 387                                         0 => {
 388                                                 let claim_request = Readable::read(reader)?;
 389                                                 OnchainEvent::Claim {
 390                                                         claim_request
 391                                                 }
 392                                         },
 393                                         1 => {
 394                                                 let outpoint = Readable::read(reader)?;
 395                                                 let input_material = Readable::read(reader)?;
 396                                                 OnchainEvent::ContentiousOutpoint {
 397                                                         outpoint,
 398                                                         input_material
 399                                                 }
 400                                         }
 401                                         _ => return Err(DecodeError::InvalidValue),
 402                                 };
 403                                 events.push(ev);
 404                         }
 405                         onchain_events_waiting_threshold_conf.insert(height_target, events);
 406                 }
 407                 let latest_height = Readable::read(reader)?;
 408
 409                 let mut secp_ctx = Secp256k1::new();
 410                 secp_ctx.seeded_randomize(&keys_manager.get_secure_random_bytes());
 411
 412                 Ok(OnchainTxHandler {
 413                         destination_script,
 414                         holder_commitment,
 415                         holder_htlc_sigs,
 416                         prev_holder_commitment,
 417                         prev_holder_htlc_sigs,
 418                         signer,
 419                         channel_transaction_parameters: channel_parameters,
 420                         claimable_outpoints,
 421                         pending_claim_requests,
 422                         onchain_events_waiting_threshold_conf,
 423                         latest_height,
 424                         secp_ctx,
 425                 })
 426         }
 427 }
 428
 429 impl<ChannelSigner: Sign> OnchainTxHandler<ChannelSigner> {
 430         pub(crate) fn new(destination_script: Script, signer: ChannelSigner, channel_parameters: ChannelTransactionParameters, holder_commitment: HolderCommitmentTransaction, secp_ctx: Secp256k1<secp256k1::All>) -> Self {
 431                 OnchainTxHandler {
 432                         destination_script,
 433                         holder_commitment,
 434                         holder_htlc_sigs: None,
 435                         prev_holder_commitment: None,
 436                         prev_holder_htlc_sigs: None,
 437                         signer,
 438                         channel_transaction_parameters: channel_parameters,
 439                         pending_claim_requests: HashMap::new(),
 440                         claimable_outpoints: HashMap::new(),
 441                         onchain_events_waiting_threshold_conf: HashMap::new(),
 442                         latest_height: 0,
 443
 444                         secp_ctx,
 445                 }
 446         }
 447
 448         pub(crate) fn get_witnesses_weight(inputs: &[InputDescriptors]) -> usize {
 449                 let mut tx_weight = 2; // count segwit flags
 450                 for inp in inputs {
 451                         // We use expected weight (and not actual) as signatures and time lock delays may vary
 452                         tx_weight +=  match inp {
 453                                 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
 454                                 &InputDescriptors::RevokedOfferedHTLC => {
 455                                         1 + 1 + 73 + 1 + 33 + 1 + 133
 456                                 },
 457                                 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
 458                                 &InputDescriptors::RevokedReceivedHTLC => {
 459                                         1 + 1 + 73 + 1 + 33 + 1 + 139
 460                                 },
 461                                 // number_of_witness_elements + sig_length + counterpartyhtlc_sig  + preimage_length + preimage + witness_script_length + witness_script
 462                                 &InputDescriptors::OfferedHTLC => {
 463                                         1 + 1 + 73 + 1 + 32 + 1 + 133
 464                                 },
 465                                 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
 466                                 &InputDescriptors::ReceivedHTLC => {
 467                                         1 + 1 + 73 + 1 + 1 + 1 + 139
 468                                 },
 469                                 // number_of_witness_elements + sig_length + revocation_sig + true_length + op_true + witness_script_length + witness_script
 470                                 &InputDescriptors::RevokedOutput => {
 471                                         1 + 1 + 73 + 1 + 1 + 1 + 77
 472                                 },
 473                         };
 474                 }
 475                 tx_weight
 476         }
 477
 478         /// In LN, output claimed are time-sensitive, which means we have to spend them before reaching some timelock expiration. At in-channel
 479         /// output detection, we generate a first version of a claim tx and associate to it a height timer. A height timer is an absolute block
 480         /// height than once reached we should generate a new bumped "version" of the claim tx to be sure than we safely claim outputs before
 481         /// than our counterparty can do it too. If timelock expires soon, height timer is going to be scale down in consequence to increase
 482         /// frequency of the bump and so increase our bets of success.
 483         fn get_height_timer(current_height: u32, timelock_expiration: u32) -> u32 {
 484                 if timelock_expiration <= current_height + 3 {
 485                         return current_height + 1
 486                 } else if timelock_expiration - current_height <= 15 {
 487                         return current_height + 3
 488                 }
 489                 current_height + 15
 490         }
 491
 492         /// 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
 493         /// (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.
 494         /// Panics if there are signing errors, because signing operations in reaction to on-chain events
 495         /// are not expected to fail, and if they do, we may lose funds.
 496         fn generate_claim_tx<F: Deref, L: Deref>(&mut self, height: u32, cached_claim_datas: &ClaimTxBumpMaterial, fee_estimator: &F, logger: &L) -> Option<(Option<u32>, u32, Transaction)>
 497                 where F::Target: FeeEstimator,
 498                                         L::Target: Logger,
 499         {
 500                 if cached_claim_datas.per_input_material.len() == 0 { return None } // But don't prune pending claiming request yet, we may have to resurrect HTLCs
 501                 let mut inputs = Vec::new();
 502                 for outp in cached_claim_datas.per_input_material.keys() {
 503                         log_trace!(logger, "Outpoint {}:{}", outp.txid, outp.vout);
 504                         inputs.push(TxIn {
 505                                 previous_output: *outp,
 506                                 script_sig: Script::new(),
 507                                 sequence: 0xfffffffd,
 508                                 witness: Vec::new(),
 509                         });
 510                 }
 511                 let mut bumped_tx = Transaction {
 512                         version: 2,
 513                         lock_time: 0,
 514                         input: inputs,
 515                         output: vec![TxOut {
 516                                 script_pubkey: self.destination_script.clone(),
 517                                 value: 0
 518                         }],
 519                 };
 520
 521                 macro_rules! RBF_bump {
 522                         ($amount: expr, $old_feerate: expr, $fee_estimator: expr, $predicted_weight: expr) => {
 523                                 {
 524                                         let mut used_feerate: u32;
 525                                         // If old feerate inferior to actual one given back by Fee Estimator, use it to compute new fee...
 526                                         let new_fee = if $old_feerate < $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority) {
 527                                                 let mut value = $amount;
 528                                                 if subtract_high_prio_fee!(logger, $fee_estimator, value, $predicted_weight, used_feerate) {
 529                                                         // Overflow check is done in subtract_high_prio_fee
 530                                                         ($amount - value)
 531                                                 } else {
 532                                                         log_trace!(logger, "Can't new-estimation bump new claiming tx, amount {} is too small", $amount);
 533                                                         return None;
 534                                                 }
 535                                         // ...else just increase the previous feerate by 25% (because that's a nice number)
 536                                         } else {
 537                                                 let fee = $old_feerate as u64 * ($predicted_weight as u64) / 750;
 538                                                 if $amount <= fee {
 539                                                         log_trace!(logger, "Can't 25% bump new claiming tx, amount {} is too small", $amount);
 540                                                         return None;
 541                                                 }
 542                                                 fee
 543                                         };
 544
 545                                         let previous_fee = $old_feerate as u64 * ($predicted_weight as u64) / 1000;
 546                                         let min_relay_fee = MIN_RELAY_FEE_SAT_PER_1000_WEIGHT * ($predicted_weight as u64) / 1000;
 547                                         // BIP 125 Opt-in Full Replace-by-Fee Signaling
 548                                         //      * 3. The replacement transaction pays an absolute fee of at least the sum paid by the original transactions.
 549                                         //      * 4. The replacement transaction must also pay for its own bandwidth at or above the rate set by the node's minimum relay fee setting.
 550                                         let new_fee = if new_fee < previous_fee + min_relay_fee {
 551                                                 new_fee + previous_fee + min_relay_fee - new_fee
 552                                         } else {
 553                                                 new_fee
 554                                         };
 555                                         Some((new_fee, new_fee * 1000 / ($predicted_weight as u64)))
 556                                 }
 557                         }
 558                 }
 559
 560                 // Compute new height timer to decide when we need to regenerate a new bumped version of the claim tx (if we
 561                 // didn't receive confirmation of it before, or not enough reorg-safe depth on top of it).
 562                 let new_timer = Some(Self::get_height_timer(height, cached_claim_datas.soonest_timelock));
 563                 let mut inputs_witnesses_weight = 0;
 564                 let mut amt = 0;
 565                 let mut dynamic_fee = true;
 566                 for per_outp_material in cached_claim_datas.per_input_material.values() {
 567                         match per_outp_material {
 568                                 &InputMaterial::Revoked { ref input_descriptor, ref amount, .. } => {
 569                                         inputs_witnesses_weight += Self::get_witnesses_weight(&[*input_descriptor]);
 570                                         amt += *amount;
 571                                 },
 572                                 &InputMaterial::CounterpartyHTLC { ref preimage, ref htlc, .. } => {
 573                                         inputs_witnesses_weight += Self::get_witnesses_weight(if preimage.is_some() { &[InputDescriptors::OfferedHTLC] } else { &[InputDescriptors::ReceivedHTLC] });
 574                                         amt += htlc.amount_msat / 1000;
 575                                 },
 576                                 &InputMaterial::HolderHTLC { .. } => {
 577                                         dynamic_fee = false;
 578                                 },
 579                                 &InputMaterial::Funding { .. } => {
 580                                         dynamic_fee = false;
 581                                 }
 582                         }
 583                 }
 584                 if dynamic_fee {
 585                         let predicted_weight = (bumped_tx.get_weight() + inputs_witnesses_weight) as u64;
 586                         let mut new_feerate;
 587                         // If old feerate is 0, first iteration of this claim, use normal fee calculation
 588                         if cached_claim_datas.feerate_previous != 0 {
 589                                 if let Some((new_fee, feerate)) = RBF_bump!(amt, cached_claim_datas.feerate_previous, fee_estimator, predicted_weight) {
 590                                         // If new computed fee is superior at the whole claimable amount burn all in fees
 591                                         if new_fee as u64 > amt {
 592                                                 bumped_tx.output[0].value = 0;
 593                                         } else {
 594                                                 bumped_tx.output[0].value = amt - new_fee as u64;
 595                                         }
 596                                         new_feerate = feerate;
 597                                 } else { return None; }
 598                         } else {
 599                                 if subtract_high_prio_fee!(logger, fee_estimator, amt, predicted_weight, new_feerate) {
 600                                         bumped_tx.output[0].value = amt;
 601                                 } else { return None; }
 602                         }
 603                         assert!(new_feerate != 0);
 604
 605                         for (i, (outp, per_outp_material)) in cached_claim_datas.per_input_material.iter().enumerate() {
 606                                 match per_outp_material {
 607                                         &InputMaterial::Revoked { ref per_commitment_point, ref counterparty_delayed_payment_base_key, ref counterparty_htlc_base_key, ref per_commitment_key, ref input_descriptor, ref amount, ref htlc, ref on_counterparty_tx_csv } => {
 608                                                 if let Ok(tx_keys) = TxCreationKeys::derive_new(&self.secp_ctx, &per_commitment_point, counterparty_delayed_payment_base_key, counterparty_htlc_base_key, &self.signer.pubkeys().revocation_basepoint, &self.signer.pubkeys().htlc_basepoint) {
 609
 610                                                         let witness_script = if let Some(ref htlc) = *htlc {
 611                                                                 chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &tx_keys.broadcaster_htlc_key, &tx_keys.countersignatory_htlc_key, &tx_keys.revocation_key)
 612                                                         } else {
 613                                                                 chan_utils::get_revokeable_redeemscript(&tx_keys.revocation_key, *on_counterparty_tx_csv, &tx_keys.broadcaster_delayed_payment_key)
 614                                                         };
 615
 616                                                         let sig = self.signer.sign_justice_transaction(&bumped_tx, i, *amount, &per_commitment_key, htlc, &self.secp_ctx).expect("sign justice tx");
 617                                                         bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
 618                                                         bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
 619                                                         if htlc.is_some() {
 620                                                                 bumped_tx.input[i].witness.push(tx_keys.revocation_key.clone().serialize().to_vec());
 621                                                         } else {
 622                                                                 bumped_tx.input[i].witness.push(vec!(1));
 623                                                         }
 624                                                         bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
 625
 626                                                         log_trace!(logger, "Going to broadcast Penalty Transaction {} claiming revoked {} output {} from {} with new feerate {}...", bumped_tx.txid(), if *input_descriptor == InputDescriptors::RevokedOutput { "to_holder" } else if *input_descriptor == InputDescriptors::RevokedOfferedHTLC { "offered" } else if *input_descriptor == InputDescriptors::RevokedReceivedHTLC { "received" } else { "" }, outp.vout, outp.txid, new_feerate);
 627                                                 }
 628                                         },
 629                                         &InputMaterial::CounterpartyHTLC { ref per_commitment_point, ref counterparty_delayed_payment_base_key, ref counterparty_htlc_base_key, ref preimage, ref htlc } => {
 630                                                 if let Ok(tx_keys) = TxCreationKeys::derive_new(&self.secp_ctx, &per_commitment_point, counterparty_delayed_payment_base_key, counterparty_htlc_base_key, &self.signer.pubkeys().revocation_basepoint, &self.signer.pubkeys().htlc_basepoint) {
 631                                                         let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &tx_keys.broadcaster_htlc_key, &tx_keys.countersignatory_htlc_key, &tx_keys.revocation_key);
 632
 633                                                         if !preimage.is_some() { bumped_tx.lock_time = htlc.cltv_expiry }; // Right now we don't aggregate time-locked transaction, if we do we should set lock_time before to avoid breaking hash computation
 634                                                         let sig = self.signer.sign_counterparty_htlc_transaction(&bumped_tx, i, &htlc.amount_msat / 1000, &per_commitment_point, htlc, &self.secp_ctx).expect("sign counterparty HTLC tx");
 635                                                         bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
 636                                                         bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
 637                                                         if let &Some(preimage) = preimage {
 638                                                                 bumped_tx.input[i].witness.push(preimage.0.to_vec());
 639                                                         } else {
 640                                                                 // Due to BIP146 (MINIMALIF) this must be a zero-length element to relay.
 641                                                                 bumped_tx.input[i].witness.push(vec![]);
 642                                                         }
 643                                                         bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
 644                                                         log_trace!(logger, "Going to broadcast Claim Transaction {} claiming counterparty {} htlc output {} from {} with new feerate {}...", bumped_tx.txid(), if preimage.is_some() { "offered" } else { "received" }, outp.vout, outp.txid, new_feerate);
 645                                                 }
 646                                         },
 647                                         _ => unreachable!()
 648                                 }
 649                         }
 650                         log_trace!(logger, "...with timer {}", new_timer.unwrap());
 651                         assert!(predicted_weight >= bumped_tx.get_weight() as u64);
 652                         return Some((new_timer, new_feerate as u32, bumped_tx))
 653                 } else {
 654                         for (_, (outp, per_outp_material)) in cached_claim_datas.per_input_material.iter().enumerate() {
 655                                 match per_outp_material {
 656                                         &InputMaterial::HolderHTLC { ref preimage, ref amount } => {
 657                                                 let htlc_tx = self.get_fully_signed_htlc_tx(outp, preimage);
 658                                                 if let Some(htlc_tx) = htlc_tx {
 659                                                         let feerate = (amount - htlc_tx.output[0].value) * 1000 / htlc_tx.get_weight() as u64;
 660                                                         // Timer set to $NEVER given we can't bump tx without anchor outputs
 661                                                         log_trace!(logger, "Going to broadcast Holder HTLC-{} claiming HTLC output {} from {}...", if preimage.is_some() { "Success" } else { "Timeout" }, outp.vout, outp.txid);
 662                                                         return Some((None, feerate as u32, htlc_tx));
 663                                                 }
 664                                                 return None;
 665                                         },
 666                                         &InputMaterial::Funding { ref funding_redeemscript } => {
 667                                                 let signed_tx = self.get_fully_signed_holder_tx(funding_redeemscript);
 668                                                 // Timer set to $NEVER given we can't bump tx without anchor outputs
 669                                                 log_trace!(logger, "Going to broadcast Holder Transaction {} claiming funding output {} from {}...", signed_tx.txid(), outp.vout, outp.txid);
 670                                                 return Some((None, self.holder_commitment.feerate_per_kw(), signed_tx));
 671                                         }
 672                                         _ => unreachable!()
 673                                 }
 674                         }
 675                 }
 676                 None
 677         }
 678
 679         /// Upon channelmonitor.block_connected(..) or upon provision of a preimage on the forward link
 680         /// for this channel, provide new relevant on-chain transactions and/or new claim requests.
 681         /// Formerly this was named `block_connected`, but it is now also used for claiming an HTLC output
 682         /// if we receive a preimage after force-close.
 683         pub(crate) fn update_claims_view<B: Deref, F: Deref, L: Deref>(&mut self, txn_matched: &[&Transaction], claimable_outpoints: Vec<ClaimRequest>, latest_height: Option<u32>, broadcaster: &B, fee_estimator: &F, logger: &L)
 684                 where B::Target: BroadcasterInterface,
 685                       F::Target: FeeEstimator,
 686                                         L::Target: Logger,
 687         {
 688                 let height = match latest_height {
 689                         Some(h) => h,
 690                         None => self.latest_height,
 691                 };
 692                 log_trace!(logger, "Updating claims view at height {} with {} matched transactions and {} claim requests", height, txn_matched.len(), claimable_outpoints.len());
 693                 let mut new_claims = Vec::new();
 694                 let mut aggregated_claim = HashMap::new();
 695                 let mut aggregated_soonest = ::std::u32::MAX;
 696
 697                 // Try to aggregate outputs if their timelock expiration isn't imminent (absolute_timelock
 698                 // <= CLTV_SHARED_CLAIM_BUFFER) and they don't require an immediate nLockTime (aggregable).
 699                 for req in claimable_outpoints {
 700                         // Don't claim a outpoint twice that would be bad for privacy and may uselessly lock a CPFP input for a while
 701                         if let Some(_) = self.claimable_outpoints.get(&req.outpoint) { log_trace!(logger, "Bouncing off outpoint {}:{}, already registered its claiming request", req.outpoint.txid, req.outpoint.vout); } else {
 702                                 log_trace!(logger, "Test if outpoint can be aggregated with expiration {} against {}", req.absolute_timelock, height + CLTV_SHARED_CLAIM_BUFFER);
 703                                 if req.absolute_timelock <= height + CLTV_SHARED_CLAIM_BUFFER || !req.aggregable { // Don't aggregate if outpoint absolute timelock is soon or marked as non-aggregable
 704                                         let mut single_input = HashMap::new();
 705                                         single_input.insert(req.outpoint, req.witness_data);
 706                                         new_claims.push((req.absolute_timelock, single_input));
 707                                 } else {
 708                                         aggregated_claim.insert(req.outpoint, req.witness_data);
 709                                         if req.absolute_timelock < aggregated_soonest {
 710                                                 aggregated_soonest = req.absolute_timelock;
 711                                         }
 712                                 }
 713                         }
 714                 }
 715                 new_claims.push((aggregated_soonest, aggregated_claim));
 716
 717                 // Generate claim transactions and track them to bump if necessary at
 718                 // height timer expiration (i.e in how many blocks we're going to take action).
 719                 for (soonest_timelock, claim) in new_claims.drain(..) {
 720                         let mut claim_material = ClaimTxBumpMaterial { height_timer: None, feerate_previous: 0, soonest_timelock, per_input_material: claim };
 721                         if let Some((new_timer, new_feerate, tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator, &*logger) {
 722                                 claim_material.height_timer = new_timer;
 723                                 claim_material.feerate_previous = new_feerate;
 724                                 let txid = tx.txid();
 725                                 for k in claim_material.per_input_material.keys() {
 726                                         log_trace!(logger, "Registering claiming request for {}:{}", k.txid, k.vout);
 727                                         self.claimable_outpoints.insert(k.clone(), (txid, height));
 728                                 }
 729                                 self.pending_claim_requests.insert(txid, claim_material);
 730                                 log_trace!(logger, "Broadcast onchain {}", log_tx!(tx));
 731                                 broadcaster.broadcast_transaction(&tx);
 732                         }
 733                 }
 734
 735                 let mut bump_candidates = HashMap::new();
 736                 for tx in txn_matched {
 737                         // Scan all input to verify is one of the outpoint spent is of interest for us
 738                         let mut claimed_outputs_material = Vec::new();
 739                         for inp in &tx.input {
 740                                 if let Some(first_claim_txid_height) = self.claimable_outpoints.get(&inp.previous_output) {
 741                                         // If outpoint has claim request pending on it...
 742                                         if let Some(claim_material) = self.pending_claim_requests.get_mut(&first_claim_txid_height.0) {
 743                                                 //... we need to verify equality between transaction outpoints and claim request
 744                                                 // outpoints to know if transaction is the original claim or a bumped one issued
 745                                                 // by us.
 746                                                 let mut set_equality = true;
 747                                                 if claim_material.per_input_material.len() != tx.input.len() {
 748                                                         set_equality = false;
 749                                                 } else {
 750                                                         for (claim_inp, tx_inp) in claim_material.per_input_material.keys().zip(tx.input.iter()) {
 751                                                                 if *claim_inp != tx_inp.previous_output {
 752                                                                         set_equality = false;
 753                                                                 }
 754                                                         }
 755                                                 }
 756
 757                                                 macro_rules! clean_claim_request_after_safety_delay {
 758                                                         () => {
 759                                                                 let new_event = OnchainEvent::Claim { claim_request: first_claim_txid_height.0.clone() };
 760                                                                 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
 761                                                                         hash_map::Entry::Occupied(mut entry) => {
 762                                                                                 if !entry.get().contains(&new_event) {
 763                                                                                         entry.get_mut().push(new_event);
 764                                                                                 }
 765                                                                         },
 766                                                                         hash_map::Entry::Vacant(entry) => {
 767                                                                                 entry.insert(vec![new_event]);
 768                                                                         }
 769                                                                 }
 770                                                         }
 771                                                 }
 772
 773                                                 // If this is our transaction (or our counterparty spent all the outputs
 774                                                 // before we could anyway with same inputs order than us), wait for
 775                                                 // ANTI_REORG_DELAY and clean the RBF tracking map.
 776                                                 if set_equality {
 777                                                         clean_claim_request_after_safety_delay!();
 778                                                 } else { // If false, generate new claim request with update outpoint set
 779                                                         let mut at_least_one_drop = false;
 780                                                         for input in tx.input.iter() {
 781                                                                 if let Some(input_material) = claim_material.per_input_material.remove(&input.previous_output) {
 782                                                                         claimed_outputs_material.push((input.previous_output, input_material));
 783                                                                         at_least_one_drop = true;
 784                                                                 }
 785                                                                 // If there are no outpoints left to claim in this request, drop it entirely after ANTI_REORG_DELAY.
 786                                                                 if claim_material.per_input_material.is_empty() {
 787                                                                         clean_claim_request_after_safety_delay!();
 788                                                                 }
 789                                                         }
 790                                                         //TODO: recompute soonest_timelock to avoid wasting a bit on fees
 791                                                         if at_least_one_drop {
 792                                                                 bump_candidates.insert(first_claim_txid_height.0.clone(), claim_material.clone());
 793                                                         }
 794                                                 }
 795                                                 break; //No need to iterate further, either tx is our or their
 796                                         } else {
 797                                                 panic!("Inconsistencies between pending_claim_requests map and claimable_outpoints map");
 798                                         }
 799                                 }
 800                         }
 801                         for (outpoint, input_material) in claimed_outputs_material.drain(..) {
 802                                 let new_event = OnchainEvent::ContentiousOutpoint { outpoint, input_material };
 803                                 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
 804                                         hash_map::Entry::Occupied(mut entry) => {
 805                                                 if !entry.get().contains(&new_event) {
 806                                                         entry.get_mut().push(new_event);
 807                                                 }
 808                                         },
 809                                         hash_map::Entry::Vacant(entry) => {
 810                                                 entry.insert(vec![new_event]);
 811                                         }
 812                                 }
 813                         }
 814                 }
 815
 816                 // After security delay, either our claim tx got enough confs or outpoint is definetely out of reach
 817                 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&height) {
 818                         for ev in events {
 819                                 match ev {
 820                                         OnchainEvent::Claim { claim_request } => {
 821                                                 // We may remove a whole set of claim outpoints here, as these one may have
 822                                                 // been aggregated in a single tx and claimed so atomically
 823                                                 if let Some(bump_material) = self.pending_claim_requests.remove(&claim_request) {
 824                                                         for outpoint in bump_material.per_input_material.keys() {
 825                                                                 self.claimable_outpoints.remove(&outpoint);
 826                                                         }
 827                                                 }
 828                                         },
 829                                         OnchainEvent::ContentiousOutpoint { outpoint, .. } => {
 830                                                 self.claimable_outpoints.remove(&outpoint);
 831                                         }
 832                                 }
 833                         }
 834                 }
 835
 836                 // Check if any pending claim request must be rescheduled
 837                 for (first_claim_txid, ref claim_data) in self.pending_claim_requests.iter() {
 838                         if let Some(h) = claim_data.height_timer {
 839                                 if h == height {
 840                                         bump_candidates.insert(*first_claim_txid, (*claim_data).clone());
 841                                 }
 842                         }
 843                 }
 844
 845                 // Build, bump and rebroadcast tx accordingly
 846                 log_trace!(logger, "Bumping {} candidates", bump_candidates.len());
 847                 for (first_claim_txid, claim_material) in bump_candidates.iter() {
 848                         if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator, &*logger) {
 849                                 log_trace!(logger, "Broadcast onchain {}", log_tx!(bump_tx));
 850                                 broadcaster.broadcast_transaction(&bump_tx);
 851                                 if let Some(claim_material) = self.pending_claim_requests.get_mut(first_claim_txid) {
 852                                         claim_material.height_timer = new_timer;
 853                                         claim_material.feerate_previous = new_feerate;
 854                                 }
 855                         }
 856                 }
 857         }
 858
 859         pub(crate) fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, height: u32, broadcaster: B, fee_estimator: F, logger: L)
 860                 where B::Target: BroadcasterInterface,
 861                       F::Target: FeeEstimator,
 862                                         L::Target: Logger,
 863         {
 864                 let mut bump_candidates = HashMap::new();
 865                 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&(height + ANTI_REORG_DELAY - 1)) {
 866                         //- our claim tx on a commitment tx output
 867                         //- resurect outpoint back in its claimable set and regenerate tx
 868                         for ev in events {
 869                                 match ev {
 870                                         OnchainEvent::ContentiousOutpoint { outpoint, input_material } => {
 871                                                 if let Some(ancestor_claimable_txid) = self.claimable_outpoints.get(&outpoint) {
 872                                                         if let Some(claim_material) = self.pending_claim_requests.get_mut(&ancestor_claimable_txid.0) {
 873                                                                 claim_material.per_input_material.insert(outpoint, input_material);
 874                                                                 // Using a HashMap guarantee us than if we have multiple outpoints getting
 875                                                                 // resurrected only one bump claim tx is going to be broadcast
 876                                                                 bump_candidates.insert(ancestor_claimable_txid.clone(), claim_material.clone());
 877                                                         }
 878                                                 }
 879                                         },
 880                                         _ => {},
 881                                 }
 882                         }
 883                 }
 884                 for (_, claim_material) in bump_candidates.iter_mut() {
 885                         if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &claim_material, &&*fee_estimator, &&*logger) {
 886                                 claim_material.height_timer = new_timer;
 887                                 claim_material.feerate_previous = new_feerate;
 888                                 broadcaster.broadcast_transaction(&bump_tx);
 889                         }
 890                 }
 891                 for (ancestor_claim_txid, claim_material) in bump_candidates.drain() {
 892                         self.pending_claim_requests.insert(ancestor_claim_txid.0, claim_material);
 893                 }
 894                 //TODO: if we implement cross-block aggregated claim transaction we need to refresh set of outpoints and regenerate tx but
 895                 // right now if one of the outpoint get disconnected, just erase whole pending claim request.
 896                 let mut remove_request = Vec::new();
 897                 self.claimable_outpoints.retain(|_, ref v|
 898                         if v.1 == height {
 899                         remove_request.push(v.0.clone());
 900                         false
 901                         } else { true });
 902                 for req in remove_request {
 903                         self.pending_claim_requests.remove(&req);
 904                 }
 905         }
 906
 907         pub(crate) fn provide_latest_holder_tx(&mut self, tx: HolderCommitmentTransaction) {
 908                 self.prev_holder_commitment = Some(replace(&mut self.holder_commitment, tx));
 909                 self.holder_htlc_sigs = None;
 910         }
 911
 912         // Normally holder HTLCs are signed at the same time as the holder commitment tx.  However,
 913         // in some configurations, the holder commitment tx has been signed and broadcast by a
 914         // ChannelMonitor replica, so we handle that case here.
 915         fn sign_latest_holder_htlcs(&mut self) {
 916                 if self.holder_htlc_sigs.is_none() {
 917                         let (_sig, sigs) = self.signer.sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("sign holder commitment");
 918                         self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, sigs));
 919                 }
 920         }
 921
 922         // Normally only the latest commitment tx and HTLCs need to be signed.  However, in some
 923         // configurations we may have updated our holder commitment but a replica of the ChannelMonitor
 924         // broadcast the previous one before we sync with it.  We handle that case here.
 925         fn sign_prev_holder_htlcs(&mut self) {
 926                 if self.prev_holder_htlc_sigs.is_none() {
 927                         if let Some(ref holder_commitment) = self.prev_holder_commitment {
 928                                 let (_sig, sigs) = self.signer.sign_holder_commitment_and_htlcs(holder_commitment, &self.secp_ctx).expect("sign previous holder commitment");
 929                                 self.prev_holder_htlc_sigs = Some(Self::extract_holder_sigs(holder_commitment, sigs));
 930                         }
 931                 }
 932         }
 933
 934         fn extract_holder_sigs(holder_commitment: &HolderCommitmentTransaction, sigs: Vec<Signature>) -> Vec<Option<(usize, Signature)>> {
 935                 let mut ret = Vec::new();
 936                 for (htlc_idx, (holder_sig, htlc)) in sigs.iter().zip(holder_commitment.htlcs().iter()).enumerate() {
 937                         let tx_idx = htlc.transaction_output_index.unwrap();
 938                         if ret.len() <= tx_idx as usize { ret.resize(tx_idx as usize + 1, None); }
 939                         ret[tx_idx as usize] = Some((htlc_idx, holder_sig.clone()));
 940                 }
 941                 ret
 942         }
 943
 944         //TODO: getting lastest holder transactions should be infallible and result in us "force-closing the channel", but we may
 945         // have empty holder commitment transaction if a ChannelMonitor is asked to force-close just after Channel::get_outbound_funding_created,
 946         // before providing a initial commitment transaction. For outbound channel, init ChannelMonitor at Channel::funding_signed, there is nothing
 947         // to monitor before.
 948         pub(crate) fn get_fully_signed_holder_tx(&mut self, funding_redeemscript: &Script) -> Transaction {
 949                 let (sig, htlc_sigs) = self.signer.sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("signing holder commitment");
 950                 self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, htlc_sigs));
 951                 self.holder_commitment.add_holder_sig(funding_redeemscript, sig)
 952         }
 953
 954         #[cfg(any(test, feature="unsafe_revoked_tx_signing"))]
 955         pub(crate) fn get_fully_signed_copy_holder_tx(&mut self, funding_redeemscript: &Script) -> Transaction {
 956                 let (sig, htlc_sigs) = self.signer.unsafe_sign_holder_commitment_and_htlcs(&self.holder_commitment, &self.secp_ctx).expect("sign holder commitment");
 957                 self.holder_htlc_sigs = Some(Self::extract_holder_sigs(&self.holder_commitment, htlc_sigs));
 958                 self.holder_commitment.add_holder_sig(funding_redeemscript, sig)
 959         }
 960
 961         pub(crate) fn get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
 962                 let mut htlc_tx = None;
 963                 let commitment_txid = self.holder_commitment.trust().txid();
 964                 // Check if the HTLC spends from the current holder commitment
 965                 if commitment_txid == outp.txid {
 966                         self.sign_latest_holder_htlcs();
 967                         if let &Some(ref htlc_sigs) = &self.holder_htlc_sigs {
 968                                 let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
 969                                 let trusted_tx = self.holder_commitment.trust();
 970                                 let counterparty_htlc_sig = self.holder_commitment.counterparty_htlc_sigs[*htlc_idx];
 971                                 htlc_tx = Some(trusted_tx
 972                                         .get_signed_htlc_tx(&self.channel_transaction_parameters.as_holder_broadcastable(), *htlc_idx, &counterparty_htlc_sig, htlc_sig, preimage));
 973                         }
 974                 }
 975                 // If the HTLC doesn't spend the current holder commitment, check if it spends the previous one
 976                 if htlc_tx.is_none() && self.prev_holder_commitment.is_some() {
 977                         let commitment_txid = self.prev_holder_commitment.as_ref().unwrap().trust().txid();
 978                         if commitment_txid == outp.txid {
 979                                 self.sign_prev_holder_htlcs();
 980                                 if let &Some(ref htlc_sigs) = &self.prev_holder_htlc_sigs {
 981                                         let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
 982                                         let holder_commitment = self.prev_holder_commitment.as_ref().unwrap();
 983                                         let trusted_tx = holder_commitment.trust();
 984                                         let counterparty_htlc_sig = holder_commitment.counterparty_htlc_sigs[*htlc_idx];
 985                                         htlc_tx = Some(trusted_tx
 986                                                 .get_signed_htlc_tx(&self.channel_transaction_parameters.as_holder_broadcastable(), *htlc_idx, &counterparty_htlc_sig, htlc_sig, preimage));
 987                                 }
 988                         }
 989                 }
 990                 htlc_tx
 991         }
 992
 993         #[cfg(any(test,feature = "unsafe_revoked_tx_signing"))]
 994         pub(crate) fn unsafe_get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
 995                 let latest_had_sigs = self.holder_htlc_sigs.is_some();
 996                 let prev_had_sigs = self.prev_holder_htlc_sigs.is_some();
 997                 let ret = self.get_fully_signed_htlc_tx(outp, preimage);
 998                 if !latest_had_sigs {
 999                         self.holder_htlc_sigs = None;
1000                 }
1001                 if !prev_had_sigs {
1002                         self.prev_holder_htlc_sigs = None;
1003                 }
1004                 ret
1005         }
1006 }