_ Git - rust-lightning/blob - lightning/src/ln/onchaintx.rs

   1 //! The logic to build claims and bump in-flight transactions until confirmations.
   2 //!
   3 //! OnchainTxHandler objetcs are fully-part of ChannelMonitor and encapsulates all
   4 //! building, tracking, bumping and notifications functions.
   5
   6 use bitcoin::blockdata::transaction::{Transaction, TxIn, TxOut, SigHashType};
   7 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
   8 use bitcoin::blockdata::script::Script;
   9 use bitcoin::util::bip143;
  10
  11 use bitcoin::hash_types::Txid;
  12
  13 use bitcoin::secp256k1::{Secp256k1, Signature};
  14 use bitcoin::secp256k1;
  15 use bitcoin::secp256k1::key::PublicKey;
  16
  17 use ln::msgs::DecodeError;
  18 use ln::channelmonitor::{ANTI_REORG_DELAY, CLTV_SHARED_CLAIM_BUFFER, InputMaterial, ClaimRequest};
  19 use ln::channelmanager::PaymentPreimage;
  20 use ln::chan_utils::{HTLCType, LocalCommitmentTransaction};
  21 use chain::chaininterface::{FeeEstimator, BroadcasterInterface, ConfirmationTarget, MIN_RELAY_FEE_SAT_PER_1000_WEIGHT};
  22 use chain::keysinterface::ChannelKeys;
  23 use util::logger::Logger;
  24 use util::ser::{Readable, Writer, Writeable};
  25 use util::byte_utils;
  26
  27 use std::collections::{HashMap, hash_map};
  28 use std::cmp;
  29 use std::ops::Deref;
  30
  31 const MAX_ALLOC_SIZE: usize = 64*1024;
  32
  33 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
  34 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
  35 #[derive(Clone, PartialEq)]
  36 enum OnchainEvent {
  37         /// Outpoint under claim process by our own tx, once this one get enough confirmations, we remove it from
  38         /// bump-txn candidate buffer.
  39         Claim {
  40                 claim_request: Txid,
  41         },
  42         /// Claim tx aggregate multiple claimable outpoints. One of the outpoint may be claimed by a remote party tx.
  43         /// In this case, we need to drop the outpoint and regenerate a new claim tx. By safety, we keep tracking
  44         /// the outpoint to be sure to resurect it back to the claim tx if reorgs happen.
  45         ContentiousOutpoint {
  46                 outpoint: BitcoinOutPoint,
  47                 input_material: InputMaterial,
  48         }
  49 }
  50
  51 /// Cache remote basepoint to compute any transaction on
  52 /// remote outputs, either justice or preimage/timeout transactions.
  53 struct RemoteTxCache {
  54         remote_delayed_payment_base_key: PublicKey,
  55         remote_htlc_base_key: PublicKey
  56 }
  57
  58 /// Higher-level cache structure needed to re-generate bumped claim txn if needed
  59 #[derive(Clone, PartialEq)]
  60 pub struct ClaimTxBumpMaterial {
  61         // At every block tick, used to check if pending claiming tx is taking too
  62         // much time for confirmation and we need to bump it.
  63         height_timer: Option<u32>,
  64         // Tracked in case of reorg to wipe out now-superflous bump material
  65         feerate_previous: u64,
  66         // Soonest timelocks among set of outpoints claimed, used to compute
  67         // a priority of not feerate
  68         soonest_timelock: u32,
  69         // Cache of script, pubkey, sig or key to solve claimable outputs scriptpubkey.
  70         per_input_material: HashMap<BitcoinOutPoint, InputMaterial>,
  71 }
  72
  73 impl Writeable for ClaimTxBumpMaterial  {
  74         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
  75                 self.height_timer.write(writer)?;
  76                 writer.write_all(&byte_utils::be64_to_array(self.feerate_previous))?;
  77                 writer.write_all(&byte_utils::be32_to_array(self.soonest_timelock))?;
  78                 writer.write_all(&byte_utils::be64_to_array(self.per_input_material.len() as u64))?;
  79                 for (outp, tx_material) in self.per_input_material.iter() {
  80                         outp.write(writer)?;
  81                         tx_material.write(writer)?;
  82                 }
  83                 Ok(())
  84         }
  85 }
  86
  87 impl Readable for ClaimTxBumpMaterial {
  88         fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
  89                 let height_timer = Readable::read(reader)?;
  90                 let feerate_previous = Readable::read(reader)?;
  91                 let soonest_timelock = Readable::read(reader)?;
  92                 let per_input_material_len: u64 = Readable::read(reader)?;
  93                 let mut per_input_material = HashMap::with_capacity(cmp::min(per_input_material_len as usize, MAX_ALLOC_SIZE / 128));
  94                 for _ in 0 ..per_input_material_len {
  95                         let outpoint = Readable::read(reader)?;
  96                         let input_material = Readable::read(reader)?;
  97                         per_input_material.insert(outpoint, input_material);
  98                 }
  99                 Ok(Self { height_timer, feerate_previous, soonest_timelock, per_input_material })
 100         }
 101 }
 102
 103 #[derive(PartialEq)]
 104 pub(super) enum InputDescriptors {
 105         RevokedOfferedHTLC,
 106         RevokedReceivedHTLC,
 107         OfferedHTLC,
 108         ReceivedHTLC,
 109         RevokedOutput, // either a revoked to_local output on commitment tx, a revoked HTLC-Timeout output or a revoked HTLC-Success output
 110 }
 111
 112 macro_rules! subtract_high_prio_fee {
 113         ($logger: ident, $fee_estimator: expr, $value: expr, $predicted_weight: expr, $used_feerate: expr) => {
 114                 {
 115                         $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority);
 116                         let mut fee = $used_feerate * ($predicted_weight as u64) / 1000;
 117                         if $value <= fee {
 118                                 $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Normal);
 119                                 fee = $used_feerate * ($predicted_weight as u64) / 1000;
 120                                 if $value <= fee {
 121                                         $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background);
 122                                         fee = $used_feerate * ($predicted_weight as u64) / 1000;
 123                                         if $value <= fee {
 124                                                 log_error!($logger, "Failed to generate an on-chain punishment tx as even low priority fee ({} sat) was more than the entire claim balance ({} sat)",
 125                                                         fee, $value);
 126                                                 false
 127                                         } else {
 128                                                 log_warn!($logger, "Used low priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
 129                                                         $value);
 130                                                 $value -= fee;
 131                                                 true
 132                                         }
 133                                 } else {
 134                                         log_warn!($logger, "Used medium priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
 135                                                 $value);
 136                                         $value -= fee;
 137                                         true
 138                                 }
 139                         } else {
 140                                 $value -= fee;
 141                                 true
 142                         }
 143                 }
 144         }
 145 }
 146
 147 impl Readable for Option<Vec<Option<(usize, Signature)>>> {
 148         fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
 149                 match Readable::read(reader)? {
 150                         0u8 => Ok(None),
 151                         1u8 => {
 152                                 let vlen: u64 = Readable::read(reader)?;
 153                                 let mut ret = Vec::with_capacity(cmp::min(vlen as usize, MAX_ALLOC_SIZE / ::std::mem::size_of::<Option<(usize, Signature)>>()));
 154                                 for _ in 0..vlen {
 155                                         ret.push(match Readable::read(reader)? {
 156                                                 0u8 => None,
 157                                                 1u8 => Some((<u64 as Readable>::read(reader)? as usize, Readable::read(reader)?)),
 158                                                 _ => return Err(DecodeError::InvalidValue)
 159                                         });
 160                                 }
 161                                 Ok(Some(ret))
 162                         },
 163                         _ => Err(DecodeError::InvalidValue),
 164                 }
 165         }
 166 }
 167
 168 impl Writeable for Option<Vec<Option<(usize, Signature)>>> {
 169         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 170                 match self {
 171                         &Some(ref vec) => {
 172                                 1u8.write(writer)?;
 173                                 (vec.len() as u64).write(writer)?;
 174                                 for opt in vec.iter() {
 175                                         match opt {
 176                                                 &Some((ref idx, ref sig)) => {
 177                                                         1u8.write(writer)?;
 178                                                         (*idx as u64).write(writer)?;
 179                                                         sig.write(writer)?;
 180                                                 },
 181                                                 &None => 0u8.write(writer)?,
 182                                         }
 183                                 }
 184                         },
 185                         &None => 0u8.write(writer)?,
 186                 }
 187                 Ok(())
 188         }
 189 }
 190
 191
 192 /// OnchainTxHandler receives claiming requests, aggregates them if it's sound, broadcast and
 193 /// do RBF bumping if possible.
 194 pub struct OnchainTxHandler<ChanSigner: ChannelKeys> {
 195         destination_script: Script,
 196         local_commitment: Option<LocalCommitmentTransaction>,
 197         // local_htlc_sigs and prev_local_htlc_sigs are in the order as they appear in the commitment
 198         // transaction outputs (hence the Option<>s inside the Vec). The first usize is the index in
 199         // the set of HTLCs in the LocalCommitmentTransaction (including those which do not appear in
 200         // the commitment transaction).
 201         local_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
 202         prev_local_commitment: Option<LocalCommitmentTransaction>,
 203         prev_local_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
 204         local_csv: u16,
 205         remote_tx_cache: RemoteTxCache,
 206         remote_csv: u16,
 207
 208         key_storage: ChanSigner,
 209
 210         // Used to track claiming requests. If claim tx doesn't confirm before height timer expiration we need to bump
 211         // it (RBF or CPFP). If an input has been part of an aggregate tx at first claim try, we need to keep it within
 212         // another bumped aggregate tx to comply with RBF rules. We may have multiple claiming txn in the flight for the
 213         // same set of outpoints. One of the outpoints may be spent by a transaction not issued by us. That's why at
 214         // block connection we scan all inputs and if any of them is among a set of a claiming request we test for set
 215         // equality between spending transaction and claim request. If true, it means transaction was one our claiming one
 216         // after a security delay of 6 blocks we remove pending claim request. If false, it means transaction wasn't and
 217         // we need to regenerate new claim request with reduced set of still-claimable outpoints.
 218         // Key is identifier of the pending claim request, i.e the txid of the initial claiming transaction generated by
 219         // us and is immutable until all outpoint of the claimable set are post-anti-reorg-delay solved.
 220         // Entry is cache of elements need to generate a bumped claiming transaction (see ClaimTxBumpMaterial)
 221         #[cfg(test)] // Used in functional_test to verify sanitization
 222         pub pending_claim_requests: HashMap<Txid, ClaimTxBumpMaterial>,
 223         #[cfg(not(test))]
 224         pending_claim_requests: HashMap<Txid, ClaimTxBumpMaterial>,
 225
 226         // Used to link outpoints claimed in a connected block to a pending claim request.
 227         // Key is outpoint than monitor parsing has detected we have keys/scripts to claim
 228         // Value is (pending claim request identifier, confirmation_block), identifier
 229         // is txid of the initial claiming transaction and is immutable until outpoint is
 230         // post-anti-reorg-delay solved, confirmaiton_block is used to erase entry if
 231         // block with output gets disconnected.
 232         #[cfg(test)] // Used in functional_test to verify sanitization
 233         pub claimable_outpoints: HashMap<BitcoinOutPoint, (Txid, u32)>,
 234         #[cfg(not(test))]
 235         claimable_outpoints: HashMap<BitcoinOutPoint, (Txid, u32)>,
 236
 237         onchain_events_waiting_threshold_conf: HashMap<u32, Vec<OnchainEvent>>,
 238
 239         secp_ctx: Secp256k1<secp256k1::All>,
 240 }
 241
 242 impl<ChanSigner: ChannelKeys + Writeable> OnchainTxHandler<ChanSigner> {
 243         pub(crate) fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 244                 self.destination_script.write(writer)?;
 245                 self.local_commitment.write(writer)?;
 246                 self.local_htlc_sigs.write(writer)?;
 247                 self.prev_local_commitment.write(writer)?;
 248                 self.prev_local_htlc_sigs.write(writer)?;
 249
 250                 self.local_csv.write(writer)?;
 251
 252                 self.remote_tx_cache.remote_delayed_payment_base_key.write(writer)?;
 253                 self.remote_tx_cache.remote_htlc_base_key.write(writer)?;
 254                 self.remote_csv.write(writer)?;
 255
 256                 self.key_storage.write(writer)?;
 257
 258                 writer.write_all(&byte_utils::be64_to_array(self.pending_claim_requests.len() as u64))?;
 259                 for (ref ancestor_claim_txid, claim_tx_data) in self.pending_claim_requests.iter() {
 260                         ancestor_claim_txid.write(writer)?;
 261                         claim_tx_data.write(writer)?;
 262                 }
 263
 264                 writer.write_all(&byte_utils::be64_to_array(self.claimable_outpoints.len() as u64))?;
 265                 for (ref outp, ref claim_and_height) in self.claimable_outpoints.iter() {
 266                         outp.write(writer)?;
 267                         claim_and_height.0.write(writer)?;
 268                         claim_and_height.1.write(writer)?;
 269                 }
 270
 271                 writer.write_all(&byte_utils::be64_to_array(self.onchain_events_waiting_threshold_conf.len() as u64))?;
 272                 for (ref target, ref events) in self.onchain_events_waiting_threshold_conf.iter() {
 273                         writer.write_all(&byte_utils::be32_to_array(**target))?;
 274                         writer.write_all(&byte_utils::be64_to_array(events.len() as u64))?;
 275                         for ev in events.iter() {
 276                                 match *ev {
 277                                         OnchainEvent::Claim { ref claim_request } => {
 278                                                 writer.write_all(&[0; 1])?;
 279                                                 claim_request.write(writer)?;
 280                                         },
 281                                         OnchainEvent::ContentiousOutpoint { ref outpoint, ref input_material } => {
 282                                                 writer.write_all(&[1; 1])?;
 283                                                 outpoint.write(writer)?;
 284                                                 input_material.write(writer)?;
 285                                         }
 286                                 }
 287                         }
 288                 }
 289                 Ok(())
 290         }
 291 }
 292
 293 impl<ChanSigner: ChannelKeys + Readable> Readable for OnchainTxHandler<ChanSigner> {
 294         fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
 295                 let destination_script = Readable::read(reader)?;
 296
 297                 let local_commitment = Readable::read(reader)?;
 298                 let local_htlc_sigs = Readable::read(reader)?;
 299                 let prev_local_commitment = Readable::read(reader)?;
 300                 let prev_local_htlc_sigs = Readable::read(reader)?;
 301
 302                 let local_csv = Readable::read(reader)?;
 303
 304                 let remote_tx_cache = {
 305                         let remote_delayed_payment_base_key = Readable::read(reader)?;
 306                         let remote_htlc_base_key = Readable::read(reader)?;
 307                         RemoteTxCache {
 308                                 remote_delayed_payment_base_key,
 309                                 remote_htlc_base_key,
 310                         }
 311                 };
 312                 let remote_csv = Readable::read(reader)?;
 313
 314                 let key_storage = Readable::read(reader)?;
 315
 316                 let pending_claim_requests_len: u64 = Readable::read(reader)?;
 317                 let mut pending_claim_requests = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
 318                 for _ in 0..pending_claim_requests_len {
 319                         pending_claim_requests.insert(Readable::read(reader)?, Readable::read(reader)?);
 320                 }
 321
 322                 let claimable_outpoints_len: u64 = Readable::read(reader)?;
 323                 let mut claimable_outpoints = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
 324                 for _ in 0..claimable_outpoints_len {
 325                         let outpoint = Readable::read(reader)?;
 326                         let ancestor_claim_txid = Readable::read(reader)?;
 327                         let height = Readable::read(reader)?;
 328                         claimable_outpoints.insert(outpoint, (ancestor_claim_txid, height));
 329                 }
 330                 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
 331                 let mut onchain_events_waiting_threshold_conf = HashMap::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
 332                 for _ in 0..waiting_threshold_conf_len {
 333                         let height_target = Readable::read(reader)?;
 334                         let events_len: u64 = Readable::read(reader)?;
 335                         let mut events = Vec::with_capacity(cmp::min(events_len as usize, MAX_ALLOC_SIZE / 128));
 336                         for _ in 0..events_len {
 337                                 let ev = match <u8 as Readable>::read(reader)? {
 338                                         0 => {
 339                                                 let claim_request = Readable::read(reader)?;
 340                                                 OnchainEvent::Claim {
 341                                                         claim_request
 342                                                 }
 343                                         },
 344                                         1 => {
 345                                                 let outpoint = Readable::read(reader)?;
 346                                                 let input_material = Readable::read(reader)?;
 347                                                 OnchainEvent::ContentiousOutpoint {
 348                                                         outpoint,
 349                                                         input_material
 350                                                 }
 351                                         }
 352                                         _ => return Err(DecodeError::InvalidValue),
 353                                 };
 354                                 events.push(ev);
 355                         }
 356                         onchain_events_waiting_threshold_conf.insert(height_target, events);
 357                 }
 358
 359                 Ok(OnchainTxHandler {
 360                         destination_script,
 361                         local_commitment,
 362                         local_htlc_sigs,
 363                         prev_local_commitment,
 364                         prev_local_htlc_sigs,
 365                         local_csv,
 366                         remote_tx_cache,
 367                         remote_csv,
 368                         key_storage,
 369                         claimable_outpoints,
 370                         pending_claim_requests,
 371                         onchain_events_waiting_threshold_conf,
 372                         secp_ctx: Secp256k1::new(),
 373                 })
 374         }
 375 }
 376
 377 impl<ChanSigner: ChannelKeys> OnchainTxHandler<ChanSigner> {
 378         pub(super) fn new(destination_script: Script, keys: ChanSigner, local_csv: u16, remote_delayed_payment_base_key: PublicKey, remote_htlc_base_key: PublicKey, remote_csv: u16) -> Self {
 379
 380                 let key_storage = keys;
 381
 382                 let remote_tx_cache = RemoteTxCache {
 383                         remote_delayed_payment_base_key,
 384                         remote_htlc_base_key,
 385                 };
 386
 387                 OnchainTxHandler {
 388                         destination_script,
 389                         local_commitment: None,
 390                         local_htlc_sigs: None,
 391                         prev_local_commitment: None,
 392                         prev_local_htlc_sigs: None,
 393                         local_csv,
 394                         remote_tx_cache,
 395                         remote_csv,
 396                         key_storage,
 397                         pending_claim_requests: HashMap::new(),
 398                         claimable_outpoints: HashMap::new(),
 399                         onchain_events_waiting_threshold_conf: HashMap::new(),
 400
 401                         secp_ctx: Secp256k1::new(),
 402                 }
 403         }
 404
 405         pub(super) fn get_witnesses_weight(inputs: &[InputDescriptors]) -> usize {
 406                 let mut tx_weight = 2; // count segwit flags
 407                 for inp in inputs {
 408                         // We use expected weight (and not actual) as signatures and time lock delays may vary
 409                         tx_weight +=  match inp {
 410                                 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
 411                                 &InputDescriptors::RevokedOfferedHTLC => {
 412                                         1 + 1 + 73 + 1 + 33 + 1 + 133
 413                                 },
 414                                 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
 415                                 &InputDescriptors::RevokedReceivedHTLC => {
 416                                         1 + 1 + 73 + 1 + 33 + 1 + 139
 417                                 },
 418                                 // number_of_witness_elements + sig_length + remotehtlc_sig  + preimage_length + preimage + witness_script_length + witness_script
 419                                 &InputDescriptors::OfferedHTLC => {
 420                                         1 + 1 + 73 + 1 + 32 + 1 + 133
 421                                 },
 422                                 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
 423                                 &InputDescriptors::ReceivedHTLC => {
 424                                         1 + 1 + 73 + 1 + 1 + 1 + 139
 425                                 },
 426                                 // number_of_witness_elements + sig_length + revocation_sig + true_length + op_true + witness_script_length + witness_script
 427                                 &InputDescriptors::RevokedOutput => {
 428                                         1 + 1 + 73 + 1 + 1 + 1 + 77
 429                                 },
 430                         };
 431                 }
 432                 tx_weight
 433         }
 434
 435         /// In LN, output claimed are time-sensitive, which means we have to spend them before reaching some timelock expiration. At in-channel
 436         /// 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
 437         /// height than once reached we should generate a new bumped "version" of the claim tx to be sure than we safely claim outputs before
 438         /// than our counterparty can do it too. If timelock expires soon, height timer is going to be scale down in consequence to increase
 439         /// frequency of the bump and so increase our bets of success.
 440         fn get_height_timer(current_height: u32, timelock_expiration: u32) -> u32 {
 441                 if timelock_expiration <= current_height + 3 {
 442                         return current_height + 1
 443                 } else if timelock_expiration - current_height <= 15 {
 444                         return current_height + 3
 445                 }
 446                 current_height + 15
 447         }
 448
 449         /// 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
 450         /// (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.
 451         fn generate_claim_tx<F: Deref, L: Deref>(&mut self, height: u32, cached_claim_datas: &ClaimTxBumpMaterial, fee_estimator: F, logger: L) -> Option<(Option<u32>, u64, Transaction)>
 452                 where F::Target: FeeEstimator,
 453                                         L::Target: Logger,
 454         {
 455                 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
 456                 let mut inputs = Vec::new();
 457                 for outp in cached_claim_datas.per_input_material.keys() {
 458                         log_trace!(logger, "Outpoint {}:{}", outp.txid, outp.vout);
 459                         inputs.push(TxIn {
 460                                 previous_output: *outp,
 461                                 script_sig: Script::new(),
 462                                 sequence: 0xfffffffd,
 463                                 witness: Vec::new(),
 464                         });
 465                 }
 466                 let mut bumped_tx = Transaction {
 467                         version: 2,
 468                         lock_time: 0,
 469                         input: inputs,
 470                         output: vec![TxOut {
 471                                 script_pubkey: self.destination_script.clone(),
 472                                 value: 0
 473                         }],
 474                 };
 475
 476                 macro_rules! RBF_bump {
 477                         ($amount: expr, $old_feerate: expr, $fee_estimator: expr, $predicted_weight: expr) => {
 478                                 {
 479                                         let mut used_feerate;
 480                                         // If old feerate inferior to actual one given back by Fee Estimator, use it to compute new fee...
 481                                         let new_fee = if $old_feerate < $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority) {
 482                                                 let mut value = $amount;
 483                                                 if subtract_high_prio_fee!(logger, $fee_estimator, value, $predicted_weight, used_feerate) {
 484                                                         // Overflow check is done in subtract_high_prio_fee
 485                                                         $amount - value
 486                                                 } else {
 487                                                         log_trace!(logger, "Can't new-estimation bump new claiming tx, amount {} is too small", $amount);
 488                                                         return None;
 489                                                 }
 490                                         // ...else just increase the previous feerate by 25% (because that's a nice number)
 491                                         } else {
 492                                                 let fee = $old_feerate * $predicted_weight / 750;
 493                                                 if $amount <= fee {
 494                                                         log_trace!(logger, "Can't 25% bump new claiming tx, amount {} is too small", $amount);
 495                                                         return None;
 496                                                 }
 497                                                 fee
 498                                         };
 499
 500                                         let previous_fee = $old_feerate * $predicted_weight / 1000;
 501                                         let min_relay_fee = MIN_RELAY_FEE_SAT_PER_1000_WEIGHT * $predicted_weight / 1000;
 502                                         // BIP 125 Opt-in Full Replace-by-Fee Signaling
 503                                         //      * 3. The replacement transaction pays an absolute fee of at least the sum paid by the original transactions.
 504                                         //      * 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.
 505                                         let new_fee = if new_fee < previous_fee + min_relay_fee {
 506                                                 new_fee + previous_fee + min_relay_fee - new_fee
 507                                         } else {
 508                                                 new_fee
 509                                         };
 510                                         Some((new_fee, new_fee * 1000 / $predicted_weight))
 511                                 }
 512                         }
 513                 }
 514
 515                 // Compute new height timer to decide when we need to regenerate a new bumped version of the claim tx (if we
 516                 // didn't receive confirmation of it before, or not enough reorg-safe depth on top of it).
 517                 let new_timer = Some(Self::get_height_timer(height, cached_claim_datas.soonest_timelock));
 518                 let mut inputs_witnesses_weight = 0;
 519                 let mut amt = 0;
 520                 let mut dynamic_fee = true;
 521                 for per_outp_material in cached_claim_datas.per_input_material.values() {
 522                         match per_outp_material {
 523                                 &InputMaterial::Revoked { ref witness_script, ref is_htlc, ref amount, .. } => {
 524                                         inputs_witnesses_weight += Self::get_witnesses_weight(if !is_htlc { &[InputDescriptors::RevokedOutput] } else if HTLCType::scriptlen_to_htlctype(witness_script.len()) == Some(HTLCType::OfferedHTLC) { &[InputDescriptors::RevokedOfferedHTLC] } else if HTLCType::scriptlen_to_htlctype(witness_script.len()) == Some(HTLCType::AcceptedHTLC) { &[InputDescriptors::RevokedReceivedHTLC] } else { unreachable!() });
 525                                         amt += *amount;
 526                                 },
 527                                 &InputMaterial::RemoteHTLC { ref preimage, ref amount, .. } => {
 528                                         inputs_witnesses_weight += Self::get_witnesses_weight(if preimage.is_some() { &[InputDescriptors::OfferedHTLC] } else { &[InputDescriptors::ReceivedHTLC] });
 529                                         amt += *amount;
 530                                 },
 531                                 &InputMaterial::LocalHTLC { .. } => {
 532                                         dynamic_fee = false;
 533                                 },
 534                                 &InputMaterial::Funding { .. } => {
 535                                         dynamic_fee = false;
 536                                 }
 537                         }
 538                 }
 539                 if dynamic_fee {
 540                         let predicted_weight = bumped_tx.get_weight() + inputs_witnesses_weight;
 541                         let mut new_feerate;
 542                         // If old feerate is 0, first iteration of this claim, use normal fee calculation
 543                         if cached_claim_datas.feerate_previous != 0 {
 544                                 if let Some((new_fee, feerate)) = RBF_bump!(amt, cached_claim_datas.feerate_previous, fee_estimator, predicted_weight as u64) {
 545                                         // If new computed fee is superior at the whole claimable amount burn all in fees
 546                                         if new_fee > amt {
 547                                                 bumped_tx.output[0].value = 0;
 548                                         } else {
 549                                                 bumped_tx.output[0].value = amt - new_fee;
 550                                         }
 551                                         new_feerate = feerate;
 552                                 } else { return None; }
 553                         } else {
 554                                 if subtract_high_prio_fee!(logger, fee_estimator, amt, predicted_weight, new_feerate) {
 555                                         bumped_tx.output[0].value = amt;
 556                                 } else { return None; }
 557                         }
 558                         assert!(new_feerate != 0);
 559
 560                         for (i, (outp, per_outp_material)) in cached_claim_datas.per_input_material.iter().enumerate() {
 561                                 match per_outp_material {
 562                                         &InputMaterial::Revoked { ref witness_script, ref pubkey, ref key, ref is_htlc, ref amount } => {
 563                                                 let sighash_parts = bip143::SighashComponents::new(&bumped_tx);
 564                                                 let sighash = hash_to_message!(&sighash_parts.sighash_all(&bumped_tx.input[i], &witness_script, *amount)[..]);
 565                                                 let sig = self.secp_ctx.sign(&sighash, &key);
 566                                                 bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
 567                                                 bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
 568                                                 if *is_htlc {
 569                                                         bumped_tx.input[i].witness.push(pubkey.unwrap().clone().serialize().to_vec());
 570                                                 } else {
 571                                                         bumped_tx.input[i].witness.push(vec!(1));
 572                                                 }
 573                                                 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
 574                                                 log_trace!(logger, "Going to broadcast Penalty Transaction {} claiming revoked {} output {} from {} with new feerate {}...", bumped_tx.txid(), if !is_htlc { "to_local" } else if HTLCType::scriptlen_to_htlctype(witness_script.len()) == Some(HTLCType::OfferedHTLC) { "offered" } else if HTLCType::scriptlen_to_htlctype(witness_script.len()) == Some(HTLCType::AcceptedHTLC) { "received" } else { "" }, outp.vout, outp.txid, new_feerate);
 575                                         },
 576                                         &InputMaterial::RemoteHTLC { ref witness_script, ref key, ref preimage, ref amount, ref locktime } => {
 577                                                 if !preimage.is_some() { bumped_tx.lock_time = *locktime }; // Right now we don't aggregate time-locked transaction, if we do we should set lock_time before to avoid breaking hash computation
 578                                                 let sighash_parts = bip143::SighashComponents::new(&bumped_tx);
 579                                                 let sighash = hash_to_message!(&sighash_parts.sighash_all(&bumped_tx.input[i], &witness_script, *amount)[..]);
 580                                                 let sig = self.secp_ctx.sign(&sighash, &key);
 581                                                 bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
 582                                                 bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
 583                                                 if let &Some(preimage) = preimage {
 584                                                         bumped_tx.input[i].witness.push(preimage.clone().0.to_vec());
 585                                                 } else {
 586                                                         bumped_tx.input[i].witness.push(vec![]);
 587                                                 }
 588                                                 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
 589                                                 log_trace!(logger, "Going to broadcast Claim Transaction {} claiming remote {} htlc output {} from {} with new feerate {}...", bumped_tx.txid(), if preimage.is_some() { "offered" } else { "received" }, outp.vout, outp.txid, new_feerate);
 590                                         },
 591                                         _ => unreachable!()
 592                                 }
 593                         }
 594                         log_trace!(logger, "...with timer {}", new_timer.unwrap());
 595                         assert!(predicted_weight >= bumped_tx.get_weight());
 596                         return Some((new_timer, new_feerate, bumped_tx))
 597                 } else {
 598                         for (_, (outp, per_outp_material)) in cached_claim_datas.per_input_material.iter().enumerate() {
 599                                 match per_outp_material {
 600                                         &InputMaterial::LocalHTLC { ref preimage, ref amount } => {
 601                                                 let htlc_tx = self.get_fully_signed_htlc_tx(outp, preimage);
 602                                                 if let Some(htlc_tx) = htlc_tx {
 603                                                         let feerate = (amount - htlc_tx.output[0].value) * 1000 / htlc_tx.get_weight() as u64;
 604                                                         // Timer set to $NEVER given we can't bump tx without anchor outputs
 605                                                         log_trace!(logger, "Going to broadcast Local HTLC-{} claiming HTLC output {} from {}...", if preimage.is_some() { "Success" } else { "Timeout" }, outp.vout, outp.txid);
 606                                                         return Some((None, feerate, htlc_tx));
 607                                                 }
 608                                                 return None;
 609                                         },
 610                                         &InputMaterial::Funding { ref funding_redeemscript } => {
 611                                                 let signed_tx = self.get_fully_signed_local_tx(funding_redeemscript).unwrap();
 612                                                 // Timer set to $NEVER given we can't bump tx without anchor outputs
 613                                                 log_trace!(logger, "Going to broadcast Local Transaction {} claiming funding output {} from {}...", signed_tx.txid(), outp.vout, outp.txid);
 614                                                 return Some((None, self.local_commitment.as_ref().unwrap().feerate_per_kw, signed_tx));
 615                                         }
 616                                         _ => unreachable!()
 617                                 }
 618                         }
 619                 }
 620                 None
 621         }
 622
 623         pub(super) fn block_connected<B: Deref, F: Deref, L: Deref>(&mut self, txn_matched: &[&Transaction], claimable_outpoints: Vec<ClaimRequest>, height: u32, broadcaster: B, fee_estimator: F, logger: L)
 624                 where B::Target: BroadcasterInterface,
 625                       F::Target: FeeEstimator,
 626                                         L::Target: Logger,
 627         {
 628                 log_trace!(logger, "Block at height {} connected with {} claim requests", height, claimable_outpoints.len());
 629                 let mut new_claims = Vec::new();
 630                 let mut aggregated_claim = HashMap::new();
 631                 let mut aggregated_soonest = ::std::u32::MAX;
 632
 633                 // Try to aggregate outputs if their timelock expiration isn't imminent (absolute_timelock
 634                 // <= CLTV_SHARED_CLAIM_BUFFER) and they don't require an immediate nLockTime (aggregable).
 635                 for req in claimable_outpoints {
 636                         // Don't claim a outpoint twice that would be bad for privacy and may uselessly lock a CPFP input for a while
 637                         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 {
 638                                 log_trace!(logger, "Test if outpoint can be aggregated with expiration {} against {}", req.absolute_timelock, height + CLTV_SHARED_CLAIM_BUFFER);
 639                                 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
 640                                         let mut single_input = HashMap::new();
 641                                         single_input.insert(req.outpoint, req.witness_data);
 642                                         new_claims.push((req.absolute_timelock, single_input));
 643                                 } else {
 644                                         aggregated_claim.insert(req.outpoint, req.witness_data);
 645                                         if req.absolute_timelock < aggregated_soonest {
 646                                                 aggregated_soonest = req.absolute_timelock;
 647                                         }
 648                                 }
 649                         }
 650                 }
 651                 new_claims.push((aggregated_soonest, aggregated_claim));
 652
 653                 // Generate claim transactions and track them to bump if necessary at
 654                 // height timer expiration (i.e in how many blocks we're going to take action).
 655                 for (soonest_timelock, claim) in new_claims.drain(..) {
 656                         let mut claim_material = ClaimTxBumpMaterial { height_timer: None, feerate_previous: 0, soonest_timelock, per_input_material: claim };
 657                         if let Some((new_timer, new_feerate, tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator, &*logger) {
 658                                 claim_material.height_timer = new_timer;
 659                                 claim_material.feerate_previous = new_feerate;
 660                                 let txid = tx.txid();
 661                                 for k in claim_material.per_input_material.keys() {
 662                                         log_trace!(logger, "Registering claiming request for {}:{}", k.txid, k.vout);
 663                                         self.claimable_outpoints.insert(k.clone(), (txid, height));
 664                                 }
 665                                 self.pending_claim_requests.insert(txid, claim_material);
 666                                 log_trace!(logger, "Broadcast onchain {}", log_tx!(tx));
 667                                 broadcaster.broadcast_transaction(&tx);
 668                         }
 669                 }
 670
 671                 let mut bump_candidates = HashMap::new();
 672                 for tx in txn_matched {
 673                         // Scan all input to verify is one of the outpoint spent is of interest for us
 674                         let mut claimed_outputs_material = Vec::new();
 675                         for inp in &tx.input {
 676                                 if let Some(first_claim_txid_height) = self.claimable_outpoints.get(&inp.previous_output) {
 677                                         // If outpoint has claim request pending on it...
 678                                         if let Some(claim_material) = self.pending_claim_requests.get_mut(&first_claim_txid_height.0) {
 679                                                 //... we need to verify equality between transaction outpoints and claim request
 680                                                 // outpoints to know if transaction is the original claim or a bumped one issued
 681                                                 // by us.
 682                                                 let mut set_equality = true;
 683                                                 if claim_material.per_input_material.len() != tx.input.len() {
 684                                                         set_equality = false;
 685                                                 } else {
 686                                                         for (claim_inp, tx_inp) in claim_material.per_input_material.keys().zip(tx.input.iter()) {
 687                                                                 if *claim_inp != tx_inp.previous_output {
 688                                                                         set_equality = false;
 689                                                                 }
 690                                                         }
 691                                                 }
 692
 693                                                 macro_rules! clean_claim_request_after_safety_delay {
 694                                                         () => {
 695                                                                 let new_event = OnchainEvent::Claim { claim_request: first_claim_txid_height.0.clone() };
 696                                                                 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
 697                                                                         hash_map::Entry::Occupied(mut entry) => {
 698                                                                                 if !entry.get().contains(&new_event) {
 699                                                                                         entry.get_mut().push(new_event);
 700                                                                                 }
 701                                                                         },
 702                                                                         hash_map::Entry::Vacant(entry) => {
 703                                                                                 entry.insert(vec![new_event]);
 704                                                                         }
 705                                                                 }
 706                                                         }
 707                                                 }
 708
 709                                                 // If this is our transaction (or our counterparty spent all the outputs
 710                                                 // before we could anyway with same inputs order than us), wait for
 711                                                 // ANTI_REORG_DELAY and clean the RBF tracking map.
 712                                                 if set_equality {
 713                                                         clean_claim_request_after_safety_delay!();
 714                                                 } else { // If false, generate new claim request with update outpoint set
 715                                                         let mut at_least_one_drop = false;
 716                                                         for input in tx.input.iter() {
 717                                                                 if let Some(input_material) = claim_material.per_input_material.remove(&input.previous_output) {
 718                                                                         claimed_outputs_material.push((input.previous_output, input_material));
 719                                                                         at_least_one_drop = true;
 720                                                                 }
 721                                                                 // If there are no outpoints left to claim in this request, drop it entirely after ANTI_REORG_DELAY.
 722                                                                 if claim_material.per_input_material.is_empty() {
 723                                                                         clean_claim_request_after_safety_delay!();
 724                                                                 }
 725                                                         }
 726                                                         //TODO: recompute soonest_timelock to avoid wasting a bit on fees
 727                                                         if at_least_one_drop {
 728                                                                 bump_candidates.insert(first_claim_txid_height.0.clone(), claim_material.clone());
 729                                                         }
 730                                                 }
 731                                                 break; //No need to iterate further, either tx is our or their
 732                                         } else {
 733                                                 panic!("Inconsistencies between pending_claim_requests map and claimable_outpoints map");
 734                                         }
 735                                 }
 736                         }
 737                         for (outpoint, input_material) in claimed_outputs_material.drain(..) {
 738                                 let new_event = OnchainEvent::ContentiousOutpoint { outpoint, input_material };
 739                                 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
 740                                         hash_map::Entry::Occupied(mut entry) => {
 741                                                 if !entry.get().contains(&new_event) {
 742                                                         entry.get_mut().push(new_event);
 743                                                 }
 744                                         },
 745                                         hash_map::Entry::Vacant(entry) => {
 746                                                 entry.insert(vec![new_event]);
 747                                         }
 748                                 }
 749                         }
 750                 }
 751
 752                 // After security delay, either our claim tx got enough confs or outpoint is definetely out of reach
 753                 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&height) {
 754                         for ev in events {
 755                                 match ev {
 756                                         OnchainEvent::Claim { claim_request } => {
 757                                                 // We may remove a whole set of claim outpoints here, as these one may have
 758                                                 // been aggregated in a single tx and claimed so atomically
 759                                                 if let Some(bump_material) = self.pending_claim_requests.remove(&claim_request) {
 760                                                         for outpoint in bump_material.per_input_material.keys() {
 761                                                                 self.claimable_outpoints.remove(&outpoint);
 762                                                         }
 763                                                 }
 764                                         },
 765                                         OnchainEvent::ContentiousOutpoint { outpoint, .. } => {
 766                                                 self.claimable_outpoints.remove(&outpoint);
 767                                         }
 768                                 }
 769                         }
 770                 }
 771
 772                 // Check if any pending claim request must be rescheduled
 773                 for (first_claim_txid, ref claim_data) in self.pending_claim_requests.iter() {
 774                         if let Some(h) = claim_data.height_timer {
 775                                 if h == height {
 776                                         bump_candidates.insert(*first_claim_txid, (*claim_data).clone());
 777                                 }
 778                         }
 779                 }
 780
 781                 // Build, bump and rebroadcast tx accordingly
 782                 log_trace!(logger, "Bumping {} candidates", bump_candidates.len());
 783                 for (first_claim_txid, claim_material) in bump_candidates.iter() {
 784                         if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator, &*logger) {
 785                                 log_trace!(logger, "Broadcast onchain {}", log_tx!(bump_tx));
 786                                 broadcaster.broadcast_transaction(&bump_tx);
 787                                 if let Some(claim_material) = self.pending_claim_requests.get_mut(first_claim_txid) {
 788                                         claim_material.height_timer = new_timer;
 789                                         claim_material.feerate_previous = new_feerate;
 790                                 }
 791                         }
 792                 }
 793         }
 794
 795         pub(super) fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, height: u32, broadcaster: B, fee_estimator: F, logger: L)
 796                 where B::Target: BroadcasterInterface,
 797                       F::Target: FeeEstimator,
 798                                         L::Target: Logger,
 799         {
 800                 let mut bump_candidates = HashMap::new();
 801                 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&(height + ANTI_REORG_DELAY - 1)) {
 802                         //- our claim tx on a commitment tx output
 803                         //- resurect outpoint back in its claimable set and regenerate tx
 804                         for ev in events {
 805                                 match ev {
 806                                         OnchainEvent::ContentiousOutpoint { outpoint, input_material } => {
 807                                                 if let Some(ancestor_claimable_txid) = self.claimable_outpoints.get(&outpoint) {
 808                                                         if let Some(claim_material) = self.pending_claim_requests.get_mut(&ancestor_claimable_txid.0) {
 809                                                                 claim_material.per_input_material.insert(outpoint, input_material);
 810                                                                 // Using a HashMap guarantee us than if we have multiple outpoints getting
 811                                                                 // resurrected only one bump claim tx is going to be broadcast
 812                                                                 bump_candidates.insert(ancestor_claimable_txid.clone(), claim_material.clone());
 813                                                         }
 814                                                 }
 815                                         },
 816                                         _ => {},
 817                                 }
 818                         }
 819                 }
 820                 for (_, claim_material) in bump_candidates.iter_mut() {
 821                         if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator, &*logger) {
 822                                 claim_material.height_timer = new_timer;
 823                                 claim_material.feerate_previous = new_feerate;
 824                                 broadcaster.broadcast_transaction(&bump_tx);
 825                         }
 826                 }
 827                 for (ancestor_claim_txid, claim_material) in bump_candidates.drain() {
 828                         self.pending_claim_requests.insert(ancestor_claim_txid.0, claim_material);
 829                 }
 830                 //TODO: if we implement cross-block aggregated claim transaction we need to refresh set of outpoints and regenerate tx but
 831                 // right now if one of the outpoint get disconnected, just erase whole pending claim request.
 832                 let mut remove_request = Vec::new();
 833                 self.claimable_outpoints.retain(|_, ref v|
 834                         if v.1 == height {
 835                         remove_request.push(v.0.clone());
 836                         false
 837                         } else { true });
 838                 for req in remove_request {
 839                         self.pending_claim_requests.remove(&req);
 840                 }
 841         }
 842
 843         pub(super) fn provide_latest_local_tx(&mut self, tx: LocalCommitmentTransaction) -> Result<(), ()> {
 844                 // To prevent any unsafe state discrepancy between offchain and onchain, once local
 845                 // commitment transaction has been signed due to an event (either block height for
 846                 // HTLC-timeout or channel force-closure), don't allow any further update of local
 847                 // commitment transaction view to avoid delivery of revocation secret to counterparty
 848                 // for the aformentionned signed transaction.
 849                 if self.local_htlc_sigs.is_some() || self.prev_local_htlc_sigs.is_some() {
 850                         return Err(());
 851                 }
 852                 self.prev_local_commitment = self.local_commitment.take();
 853                 self.local_commitment = Some(tx);
 854                 Ok(())
 855         }
 856
 857         fn sign_latest_local_htlcs(&mut self) {
 858                 if let Some(ref local_commitment) = self.local_commitment {
 859                         if let Ok(sigs) = self.key_storage.sign_local_commitment_htlc_transactions(local_commitment, self.local_csv, &self.secp_ctx) {
 860                                 self.local_htlc_sigs = Some(Vec::new());
 861                                 let ret = self.local_htlc_sigs.as_mut().unwrap();
 862                                 for (htlc_idx, (local_sig, &(ref htlc, _))) in sigs.iter().zip(local_commitment.per_htlc.iter()).enumerate() {
 863                                         if let Some(tx_idx) = htlc.transaction_output_index {
 864                                                 if ret.len() <= tx_idx as usize { ret.resize(tx_idx as usize + 1, None); }
 865                                                 ret[tx_idx as usize] = Some((htlc_idx, local_sig.expect("Did not receive a signature for a non-dust HTLC")));
 866                                         } else {
 867                                                 assert!(local_sig.is_none(), "Received a signature for a dust HTLC");
 868                                         }
 869                                 }
 870                         }
 871                 }
 872         }
 873         fn sign_prev_local_htlcs(&mut self) {
 874                 if let Some(ref local_commitment) = self.prev_local_commitment {
 875                         if let Ok(sigs) = self.key_storage.sign_local_commitment_htlc_transactions(local_commitment, self.local_csv, &self.secp_ctx) {
 876                                 self.prev_local_htlc_sigs = Some(Vec::new());
 877                                 let ret = self.prev_local_htlc_sigs.as_mut().unwrap();
 878                                 for (htlc_idx, (local_sig, &(ref htlc, _))) in sigs.iter().zip(local_commitment.per_htlc.iter()).enumerate() {
 879                                         if let Some(tx_idx) = htlc.transaction_output_index {
 880                                                 if ret.len() <= tx_idx as usize { ret.resize(tx_idx as usize + 1, None); }
 881                                                 ret[tx_idx as usize] = Some((htlc_idx, local_sig.expect("Did not receive a signature for a non-dust HTLC")));
 882                                         } else {
 883                                                 assert!(local_sig.is_none(), "Received a signature for a dust HTLC");
 884                                         }
 885                                 }
 886                         }
 887                 }
 888         }
 889
 890         //TODO: getting lastest local transactions should be infaillible and result in us "force-closing the channel", but we may
 891         // have empty local commitment transaction if a ChannelMonitor is asked to force-close just after Channel::get_outbound_funding_created,
 892         // before providing a initial commitment transaction. For outbound channel, init ChannelMonitor at Channel::funding_signed, there is nothing
 893         // to monitor before.
 894         pub(super) fn get_fully_signed_local_tx(&mut self, funding_redeemscript: &Script) -> Option<Transaction> {
 895                 if let Some(ref mut local_commitment) = self.local_commitment {
 896                         match self.key_storage.sign_local_commitment(local_commitment, &self.secp_ctx) {
 897                                 Ok(sig) => Some(local_commitment.add_local_sig(funding_redeemscript, sig)),
 898                                 Err(_) => return None,
 899                         }
 900                 } else {
 901                         None
 902                 }
 903         }
 904
 905         #[cfg(test)]
 906         pub(super) fn get_fully_signed_copy_local_tx(&mut self, funding_redeemscript: &Script) -> Option<Transaction> {
 907                 if let Some(ref mut local_commitment) = self.local_commitment {
 908                         let local_commitment = local_commitment.clone();
 909                         match self.key_storage.sign_local_commitment(&local_commitment, &self.secp_ctx) {
 910                                 Ok(sig) => Some(local_commitment.add_local_sig(funding_redeemscript, sig)),
 911                                 Err(_) => return None,
 912                         }
 913                 } else {
 914                         None
 915                 }
 916         }
 917
 918         pub(super) fn get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
 919                 let mut htlc_tx = None;
 920                 if self.local_commitment.is_some() {
 921                         let commitment_txid = self.local_commitment.as_ref().unwrap().txid();
 922                         if commitment_txid == outp.txid {
 923                                 self.sign_latest_local_htlcs();
 924                                 if let &Some(ref htlc_sigs) = &self.local_htlc_sigs {
 925                                         let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
 926                                         htlc_tx = Some(self.local_commitment.as_ref().unwrap()
 927                                                 .get_signed_htlc_tx(*htlc_idx, htlc_sig, preimage, self.local_csv));
 928                                 }
 929                         }
 930                 }
 931                 if self.prev_local_commitment.is_some() {
 932                         let commitment_txid = self.prev_local_commitment.as_ref().unwrap().txid();
 933                         if commitment_txid == outp.txid {
 934                                 self.sign_prev_local_htlcs();
 935                                 if let &Some(ref htlc_sigs) = &self.prev_local_htlc_sigs {
 936                                         let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
 937                                         htlc_tx = Some(self.prev_local_commitment.as_ref().unwrap()
 938                                                 .get_signed_htlc_tx(*htlc_idx, htlc_sig, preimage, self.local_csv));
 939                                 }
 940                         }
 941                 }
 942                 htlc_tx
 943         }
 944
 945         #[cfg(test)]
 946         pub(super) fn unsafe_get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
 947                 let latest_had_sigs = self.local_htlc_sigs.is_some();
 948                 let prev_had_sigs = self.prev_local_htlc_sigs.is_some();
 949                 let ret = self.get_fully_signed_htlc_tx(outp, preimage);
 950                 if !latest_had_sigs {
 951                         self.local_htlc_sigs = None;
 952                 }
 953                 if !prev_had_sigs {
 954                         self.prev_local_htlc_sigs = None;
 955                 }
 956                 ret
 957         }
 958 }