_ 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
  10 use bitcoin::hash_types::Txid;
  11
  12 use bitcoin::secp256k1::{Secp256k1, Signature};
  13 use bitcoin::secp256k1;
  14
  15 use ln::msgs::DecodeError;
  16 use ln::channelmonitor::{ANTI_REORG_DELAY, CLTV_SHARED_CLAIM_BUFFER, InputMaterial, ClaimRequest};
  17 use ln::channelmanager::PaymentPreimage;
  18 use ln::chan_utils;
  19 use ln::chan_utils::{TxCreationKeys, LocalCommitmentTransaction};
  20 use chain::chaininterface::{FeeEstimator, BroadcasterInterface, ConfirmationTarget, MIN_RELAY_FEE_SAT_PER_1000_WEIGHT};
  21 use chain::keysinterface::ChannelKeys;
  22 use util::logger::Logger;
  23 use util::ser::{Readable, Writer, Writeable};
  24 use util::byte_utils;
  25
  26 use std::collections::{HashMap, hash_map};
  27 use std::cmp;
  28 use std::ops::Deref;
  29
  30 const MAX_ALLOC_SIZE: usize = 64*1024;
  31
  32 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
  33 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
  34 #[derive(Clone, PartialEq)]
  35 enum OnchainEvent {
  36         /// Outpoint under claim process by our own tx, once this one get enough confirmations, we remove it from
  37         /// bump-txn candidate buffer.
  38         Claim {
  39                 claim_request: Txid,
  40         },
  41         /// Claim tx aggregate multiple claimable outpoints. One of the outpoint may be claimed by a remote party tx.
  42         /// In this case, we need to drop the outpoint and regenerate a new claim tx. By safety, we keep tracking
  43         /// the outpoint to be sure to resurect it back to the claim tx if reorgs happen.
  44         ContentiousOutpoint {
  45                 outpoint: BitcoinOutPoint,
  46                 input_material: InputMaterial,
  47         }
  48 }
  49
  50 /// Higher-level cache structure needed to re-generate bumped claim txn if needed
  51 #[derive(Clone, PartialEq)]
  52 pub struct ClaimTxBumpMaterial {
  53         // At every block tick, used to check if pending claiming tx is taking too
  54         // much time for confirmation and we need to bump it.
  55         height_timer: Option<u32>,
  56         // Tracked in case of reorg to wipe out now-superflous bump material
  57         feerate_previous: u32,
  58         // Soonest timelocks among set of outpoints claimed, used to compute
  59         // a priority of not feerate
  60         soonest_timelock: u32,
  61         // Cache of script, pubkey, sig or key to solve claimable outputs scriptpubkey.
  62         per_input_material: HashMap<BitcoinOutPoint, InputMaterial>,
  63 }
  64
  65 impl Writeable for ClaimTxBumpMaterial  {
  66         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
  67                 self.height_timer.write(writer)?;
  68                 writer.write_all(&byte_utils::be32_to_array(self.feerate_previous))?;
  69                 writer.write_all(&byte_utils::be32_to_array(self.soonest_timelock))?;
  70                 writer.write_all(&byte_utils::be64_to_array(self.per_input_material.len() as u64))?;
  71                 for (outp, tx_material) in self.per_input_material.iter() {
  72                         outp.write(writer)?;
  73                         tx_material.write(writer)?;
  74                 }
  75                 Ok(())
  76         }
  77 }
  78
  79 impl Readable for ClaimTxBumpMaterial {
  80         fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
  81                 let height_timer = Readable::read(reader)?;
  82                 let feerate_previous = Readable::read(reader)?;
  83                 let soonest_timelock = Readable::read(reader)?;
  84                 let per_input_material_len: u64 = Readable::read(reader)?;
  85                 let mut per_input_material = HashMap::with_capacity(cmp::min(per_input_material_len as usize, MAX_ALLOC_SIZE / 128));
  86                 for _ in 0 ..per_input_material_len {
  87                         let outpoint = Readable::read(reader)?;
  88                         let input_material = Readable::read(reader)?;
  89                         per_input_material.insert(outpoint, input_material);
  90                 }
  91                 Ok(Self { height_timer, feerate_previous, soonest_timelock, per_input_material })
  92         }
  93 }
  94
  95 #[derive(PartialEq, Clone, Copy)]
  96 pub(crate) enum InputDescriptors {
  97         RevokedOfferedHTLC,
  98         RevokedReceivedHTLC,
  99         OfferedHTLC,
 100         ReceivedHTLC,
 101         RevokedOutput, // either a revoked to_local output on commitment tx, a revoked HTLC-Timeout output or a revoked HTLC-Success output
 102 }
 103
 104 impl Writeable for InputDescriptors {
 105         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 106                 match self {
 107                         &InputDescriptors::RevokedOfferedHTLC => {
 108                                 writer.write_all(&[0; 1])?;
 109                         },
 110                         &InputDescriptors::RevokedReceivedHTLC => {
 111                                 writer.write_all(&[1; 1])?;
 112                         },
 113                         &InputDescriptors::OfferedHTLC => {
 114                                 writer.write_all(&[2; 1])?;
 115                         },
 116                         &InputDescriptors::ReceivedHTLC => {
 117                                 writer.write_all(&[3; 1])?;
 118                         }
 119                         &InputDescriptors::RevokedOutput => {
 120                                 writer.write_all(&[4; 1])?;
 121                         }
 122                 }
 123                 Ok(())
 124         }
 125 }
 126
 127 impl Readable for InputDescriptors {
 128         fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
 129                 let input_descriptor = match <u8 as Readable>::read(reader)? {
 130                         0 => {
 131                                 InputDescriptors::RevokedOfferedHTLC
 132                         },
 133                         1 => {
 134                                 InputDescriptors::RevokedReceivedHTLC
 135                         },
 136                         2 => {
 137                                 InputDescriptors::OfferedHTLC
 138                         },
 139                         3 => {
 140                                 InputDescriptors::ReceivedHTLC
 141                         },
 142                         4 => {
 143                                 InputDescriptors::RevokedOutput
 144                         }
 145                         _ => return Err(DecodeError::InvalidValue),
 146                 };
 147                 Ok(input_descriptor)
 148         }
 149 }
 150
 151 macro_rules! subtract_high_prio_fee {
 152         ($logger: ident, $fee_estimator: expr, $value: expr, $predicted_weight: expr, $used_feerate: expr) => {
 153                 {
 154                         $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority).into();
 155                         let mut fee = $used_feerate as u64 * $predicted_weight / 1000;
 156                         if $value <= fee {
 157                                 $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Normal).into();
 158                                 fee = $used_feerate as u64 * $predicted_weight / 1000;
 159                                 if $value <= fee.into() {
 160                                         $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background).into();
 161                                         fee = $used_feerate as u64 * $predicted_weight / 1000;
 162                                         if $value <= fee {
 163                                                 log_error!($logger, "Failed to generate an on-chain punishment tx as even low priority fee ({} sat) was more than the entire claim balance ({} sat)",
 164                                                         fee, $value);
 165                                                 false
 166                                         } else {
 167                                                 log_warn!($logger, "Used low priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
 168                                                         $value);
 169                                                 $value -= fee;
 170                                                 true
 171                                         }
 172                                 } else {
 173                                         log_warn!($logger, "Used medium priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
 174                                                 $value);
 175                                         $value -= fee;
 176                                         true
 177                                 }
 178                         } else {
 179                                 $value -= fee;
 180                                 true
 181                         }
 182                 }
 183         }
 184 }
 185
 186 impl Readable for Option<Vec<Option<(usize, Signature)>>> {
 187         fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
 188                 match Readable::read(reader)? {
 189                         0u8 => Ok(None),
 190                         1u8 => {
 191                                 let vlen: u64 = Readable::read(reader)?;
 192                                 let mut ret = Vec::with_capacity(cmp::min(vlen as usize, MAX_ALLOC_SIZE / ::std::mem::size_of::<Option<(usize, Signature)>>()));
 193                                 for _ in 0..vlen {
 194                                         ret.push(match Readable::read(reader)? {
 195                                                 0u8 => None,
 196                                                 1u8 => Some((<u64 as Readable>::read(reader)? as usize, Readable::read(reader)?)),
 197                                                 _ => return Err(DecodeError::InvalidValue)
 198                                         });
 199                                 }
 200                                 Ok(Some(ret))
 201                         },
 202                         _ => Err(DecodeError::InvalidValue),
 203                 }
 204         }
 205 }
 206
 207 impl Writeable for Option<Vec<Option<(usize, Signature)>>> {
 208         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 209                 match self {
 210                         &Some(ref vec) => {
 211                                 1u8.write(writer)?;
 212                                 (vec.len() as u64).write(writer)?;
 213                                 for opt in vec.iter() {
 214                                         match opt {
 215                                                 &Some((ref idx, ref sig)) => {
 216                                                         1u8.write(writer)?;
 217                                                         (*idx as u64).write(writer)?;
 218                                                         sig.write(writer)?;
 219                                                 },
 220                                                 &None => 0u8.write(writer)?,
 221                                         }
 222                                 }
 223                         },
 224                         &None => 0u8.write(writer)?,
 225                 }
 226                 Ok(())
 227         }
 228 }
 229
 230
 231 /// OnchainTxHandler receives claiming requests, aggregates them if it's sound, broadcast and
 232 /// do RBF bumping if possible.
 233 pub struct OnchainTxHandler<ChanSigner: ChannelKeys> {
 234         destination_script: Script,
 235         local_commitment: Option<LocalCommitmentTransaction>,
 236         // local_htlc_sigs and prev_local_htlc_sigs are in the order as they appear in the commitment
 237         // transaction outputs (hence the Option<>s inside the Vec). The first usize is the index in
 238         // the set of HTLCs in the LocalCommitmentTransaction (including those which do not appear in
 239         // the commitment transaction).
 240         local_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
 241         prev_local_commitment: Option<LocalCommitmentTransaction>,
 242         prev_local_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
 243         on_local_tx_csv: u16,
 244
 245         key_storage: ChanSigner,
 246
 247         // Used to track claiming requests. If claim tx doesn't confirm before height timer expiration we need to bump
 248         // it (RBF or CPFP). If an input has been part of an aggregate tx at first claim try, we need to keep it within
 249         // another bumped aggregate tx to comply with RBF rules. We may have multiple claiming txn in the flight for the
 250         // same set of outpoints. One of the outpoints may be spent by a transaction not issued by us. That's why at
 251         // block connection we scan all inputs and if any of them is among a set of a claiming request we test for set
 252         // equality between spending transaction and claim request. If true, it means transaction was one our claiming one
 253         // after a security delay of 6 blocks we remove pending claim request. If false, it means transaction wasn't and
 254         // we need to regenerate new claim request with reduced set of still-claimable outpoints.
 255         // Key is identifier of the pending claim request, i.e the txid of the initial claiming transaction generated by
 256         // us and is immutable until all outpoint of the claimable set are post-anti-reorg-delay solved.
 257         // Entry is cache of elements need to generate a bumped claiming transaction (see ClaimTxBumpMaterial)
 258         #[cfg(test)] // Used in functional_test to verify sanitization
 259         pub pending_claim_requests: HashMap<Txid, ClaimTxBumpMaterial>,
 260         #[cfg(not(test))]
 261         pending_claim_requests: HashMap<Txid, ClaimTxBumpMaterial>,
 262
 263         // Used to link outpoints claimed in a connected block to a pending claim request.
 264         // Key is outpoint than monitor parsing has detected we have keys/scripts to claim
 265         // Value is (pending claim request identifier, confirmation_block), identifier
 266         // is txid of the initial claiming transaction and is immutable until outpoint is
 267         // post-anti-reorg-delay solved, confirmaiton_block is used to erase entry if
 268         // block with output gets disconnected.
 269         #[cfg(test)] // Used in functional_test to verify sanitization
 270         pub claimable_outpoints: HashMap<BitcoinOutPoint, (Txid, u32)>,
 271         #[cfg(not(test))]
 272         claimable_outpoints: HashMap<BitcoinOutPoint, (Txid, u32)>,
 273
 274         onchain_events_waiting_threshold_conf: HashMap<u32, Vec<OnchainEvent>>,
 275
 276         secp_ctx: Secp256k1<secp256k1::All>,
 277 }
 278
 279 impl<ChanSigner: ChannelKeys + Writeable> OnchainTxHandler<ChanSigner> {
 280         pub(crate) fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 281                 self.destination_script.write(writer)?;
 282                 self.local_commitment.write(writer)?;
 283                 self.local_htlc_sigs.write(writer)?;
 284                 self.prev_local_commitment.write(writer)?;
 285                 self.prev_local_htlc_sigs.write(writer)?;
 286
 287                 self.on_local_tx_csv.write(writer)?;
 288
 289                 self.key_storage.write(writer)?;
 290
 291                 writer.write_all(&byte_utils::be64_to_array(self.pending_claim_requests.len() as u64))?;
 292                 for (ref ancestor_claim_txid, claim_tx_data) in self.pending_claim_requests.iter() {
 293                         ancestor_claim_txid.write(writer)?;
 294                         claim_tx_data.write(writer)?;
 295                 }
 296
 297                 writer.write_all(&byte_utils::be64_to_array(self.claimable_outpoints.len() as u64))?;
 298                 for (ref outp, ref claim_and_height) in self.claimable_outpoints.iter() {
 299                         outp.write(writer)?;
 300                         claim_and_height.0.write(writer)?;
 301                         claim_and_height.1.write(writer)?;
 302                 }
 303
 304                 writer.write_all(&byte_utils::be64_to_array(self.onchain_events_waiting_threshold_conf.len() as u64))?;
 305                 for (ref target, ref events) in self.onchain_events_waiting_threshold_conf.iter() {
 306                         writer.write_all(&byte_utils::be32_to_array(**target))?;
 307                         writer.write_all(&byte_utils::be64_to_array(events.len() as u64))?;
 308                         for ev in events.iter() {
 309                                 match *ev {
 310                                         OnchainEvent::Claim { ref claim_request } => {
 311                                                 writer.write_all(&[0; 1])?;
 312                                                 claim_request.write(writer)?;
 313                                         },
 314                                         OnchainEvent::ContentiousOutpoint { ref outpoint, ref input_material } => {
 315                                                 writer.write_all(&[1; 1])?;
 316                                                 outpoint.write(writer)?;
 317                                                 input_material.write(writer)?;
 318                                         }
 319                                 }
 320                         }
 321                 }
 322                 Ok(())
 323         }
 324 }
 325
 326 impl<ChanSigner: ChannelKeys + Readable> Readable for OnchainTxHandler<ChanSigner> {
 327         fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
 328                 let destination_script = Readable::read(reader)?;
 329
 330                 let local_commitment = Readable::read(reader)?;
 331                 let local_htlc_sigs = Readable::read(reader)?;
 332                 let prev_local_commitment = Readable::read(reader)?;
 333                 let prev_local_htlc_sigs = Readable::read(reader)?;
 334
 335                 let on_local_tx_csv = Readable::read(reader)?;
 336
 337                 let key_storage = Readable::read(reader)?;
 338
 339                 let pending_claim_requests_len: u64 = Readable::read(reader)?;
 340                 let mut pending_claim_requests = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
 341                 for _ in 0..pending_claim_requests_len {
 342                         pending_claim_requests.insert(Readable::read(reader)?, Readable::read(reader)?);
 343                 }
 344
 345                 let claimable_outpoints_len: u64 = Readable::read(reader)?;
 346                 let mut claimable_outpoints = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
 347                 for _ in 0..claimable_outpoints_len {
 348                         let outpoint = Readable::read(reader)?;
 349                         let ancestor_claim_txid = Readable::read(reader)?;
 350                         let height = Readable::read(reader)?;
 351                         claimable_outpoints.insert(outpoint, (ancestor_claim_txid, height));
 352                 }
 353                 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
 354                 let mut onchain_events_waiting_threshold_conf = HashMap::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
 355                 for _ in 0..waiting_threshold_conf_len {
 356                         let height_target = Readable::read(reader)?;
 357                         let events_len: u64 = Readable::read(reader)?;
 358                         let mut events = Vec::with_capacity(cmp::min(events_len as usize, MAX_ALLOC_SIZE / 128));
 359                         for _ in 0..events_len {
 360                                 let ev = match <u8 as Readable>::read(reader)? {
 361                                         0 => {
 362                                                 let claim_request = Readable::read(reader)?;
 363                                                 OnchainEvent::Claim {
 364                                                         claim_request
 365                                                 }
 366                                         },
 367                                         1 => {
 368                                                 let outpoint = Readable::read(reader)?;
 369                                                 let input_material = Readable::read(reader)?;
 370                                                 OnchainEvent::ContentiousOutpoint {
 371                                                         outpoint,
 372                                                         input_material
 373                                                 }
 374                                         }
 375                                         _ => return Err(DecodeError::InvalidValue),
 376                                 };
 377                                 events.push(ev);
 378                         }
 379                         onchain_events_waiting_threshold_conf.insert(height_target, events);
 380                 }
 381
 382                 Ok(OnchainTxHandler {
 383                         destination_script,
 384                         local_commitment,
 385                         local_htlc_sigs,
 386                         prev_local_commitment,
 387                         prev_local_htlc_sigs,
 388                         on_local_tx_csv,
 389                         key_storage,
 390                         claimable_outpoints,
 391                         pending_claim_requests,
 392                         onchain_events_waiting_threshold_conf,
 393                         secp_ctx: Secp256k1::new(),
 394                 })
 395         }
 396 }
 397
 398 impl<ChanSigner: ChannelKeys> OnchainTxHandler<ChanSigner> {
 399         pub(super) fn new(destination_script: Script, keys: ChanSigner, on_local_tx_csv: u16) -> Self {
 400
 401                 let key_storage = keys;
 402
 403                 OnchainTxHandler {
 404                         destination_script,
 405                         local_commitment: None,
 406                         local_htlc_sigs: None,
 407                         prev_local_commitment: None,
 408                         prev_local_htlc_sigs: None,
 409                         on_local_tx_csv,
 410                         key_storage,
 411                         pending_claim_requests: HashMap::new(),
 412                         claimable_outpoints: HashMap::new(),
 413                         onchain_events_waiting_threshold_conf: HashMap::new(),
 414
 415                         secp_ctx: Secp256k1::new(),
 416                 }
 417         }
 418
 419         pub(super) fn get_witnesses_weight(inputs: &[InputDescriptors]) -> usize {
 420                 let mut tx_weight = 2; // count segwit flags
 421                 for inp in inputs {
 422                         // We use expected weight (and not actual) as signatures and time lock delays may vary
 423                         tx_weight +=  match inp {
 424                                 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
 425                                 &InputDescriptors::RevokedOfferedHTLC => {
 426                                         1 + 1 + 73 + 1 + 33 + 1 + 133
 427                                 },
 428                                 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
 429                                 &InputDescriptors::RevokedReceivedHTLC => {
 430                                         1 + 1 + 73 + 1 + 33 + 1 + 139
 431                                 },
 432                                 // number_of_witness_elements + sig_length + remotehtlc_sig  + preimage_length + preimage + witness_script_length + witness_script
 433                                 &InputDescriptors::OfferedHTLC => {
 434                                         1 + 1 + 73 + 1 + 32 + 1 + 133
 435                                 },
 436                                 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
 437                                 &InputDescriptors::ReceivedHTLC => {
 438                                         1 + 1 + 73 + 1 + 1 + 1 + 139
 439                                 },
 440                                 // number_of_witness_elements + sig_length + revocation_sig + true_length + op_true + witness_script_length + witness_script
 441                                 &InputDescriptors::RevokedOutput => {
 442                                         1 + 1 + 73 + 1 + 1 + 1 + 77
 443                                 },
 444                         };
 445                 }
 446                 tx_weight
 447         }
 448
 449         /// In LN, output claimed are time-sensitive, which means we have to spend them before reaching some timelock expiration. At in-channel
 450         /// 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
 451         /// height than once reached we should generate a new bumped "version" of the claim tx to be sure than we safely claim outputs before
 452         /// than our counterparty can do it too. If timelock expires soon, height timer is going to be scale down in consequence to increase
 453         /// frequency of the bump and so increase our bets of success.
 454         fn get_height_timer(current_height: u32, timelock_expiration: u32) -> u32 {
 455                 if timelock_expiration <= current_height + 3 {
 456                         return current_height + 1
 457                 } else if timelock_expiration - current_height <= 15 {
 458                         return current_height + 3
 459                 }
 460                 current_height + 15
 461         }
 462
 463         /// 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
 464         /// (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.
 465         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)>
 466                 where F::Target: FeeEstimator,
 467                                         L::Target: Logger,
 468         {
 469                 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
 470                 let mut inputs = Vec::new();
 471                 for outp in cached_claim_datas.per_input_material.keys() {
 472                         log_trace!(logger, "Outpoint {}:{}", outp.txid, outp.vout);
 473                         inputs.push(TxIn {
 474                                 previous_output: *outp,
 475                                 script_sig: Script::new(),
 476                                 sequence: 0xfffffffd,
 477                                 witness: Vec::new(),
 478                         });
 479                 }
 480                 let mut bumped_tx = Transaction {
 481                         version: 2,
 482                         lock_time: 0,
 483                         input: inputs,
 484                         output: vec![TxOut {
 485                                 script_pubkey: self.destination_script.clone(),
 486                                 value: 0
 487                         }],
 488                 };
 489
 490                 macro_rules! RBF_bump {
 491                         ($amount: expr, $old_feerate: expr, $fee_estimator: expr, $predicted_weight: expr) => {
 492                                 {
 493                                         let mut used_feerate: u32;
 494                                         // If old feerate inferior to actual one given back by Fee Estimator, use it to compute new fee...
 495                                         let new_fee = if $old_feerate < $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority) {
 496                                                 let mut value = $amount;
 497                                                 if subtract_high_prio_fee!(logger, $fee_estimator, value, $predicted_weight, used_feerate) {
 498                                                         // Overflow check is done in subtract_high_prio_fee
 499                                                         ($amount - value)
 500                                                 } else {
 501                                                         log_trace!(logger, "Can't new-estimation bump new claiming tx, amount {} is too small", $amount);
 502                                                         return None;
 503                                                 }
 504                                         // ...else just increase the previous feerate by 25% (because that's a nice number)
 505                                         } else {
 506                                                 let fee = $old_feerate as u64 * ($predicted_weight as u64) / 750;
 507                                                 if $amount <= fee {
 508                                                         log_trace!(logger, "Can't 25% bump new claiming tx, amount {} is too small", $amount);
 509                                                         return None;
 510                                                 }
 511                                                 fee
 512                                         };
 513
 514                                         let previous_fee = $old_feerate as u64 * ($predicted_weight as u64) / 1000;
 515                                         let min_relay_fee = MIN_RELAY_FEE_SAT_PER_1000_WEIGHT * ($predicted_weight as u64) / 1000;
 516                                         // BIP 125 Opt-in Full Replace-by-Fee Signaling
 517                                         //      * 3. The replacement transaction pays an absolute fee of at least the sum paid by the original transactions.
 518                                         //      * 4. The replacement transaction must also pay for its own bandwidth at or above the rate set by the node's minimum relay fee setting.
 519                                         let new_fee = if new_fee < previous_fee + min_relay_fee {
 520                                                 new_fee + previous_fee + min_relay_fee - new_fee
 521                                         } else {
 522                                                 new_fee
 523                                         };
 524                                         Some((new_fee, new_fee * 1000 / ($predicted_weight as u64)))
 525                                 }
 526                         }
 527                 }
 528
 529                 // Compute new height timer to decide when we need to regenerate a new bumped version of the claim tx (if we
 530                 // didn't receive confirmation of it before, or not enough reorg-safe depth on top of it).
 531                 let new_timer = Some(Self::get_height_timer(height, cached_claim_datas.soonest_timelock));
 532                 let mut inputs_witnesses_weight = 0;
 533                 let mut amt = 0;
 534                 let mut dynamic_fee = true;
 535                 for per_outp_material in cached_claim_datas.per_input_material.values() {
 536                         match per_outp_material {
 537                                 &InputMaterial::Revoked { ref input_descriptor, ref amount, .. } => {
 538                                         inputs_witnesses_weight += Self::get_witnesses_weight(&[*input_descriptor]);
 539                                         amt += *amount;
 540                                 },
 541                                 &InputMaterial::RemoteHTLC { ref preimage, ref htlc, .. } => {
 542                                         inputs_witnesses_weight += Self::get_witnesses_weight(if preimage.is_some() { &[InputDescriptors::OfferedHTLC] } else { &[InputDescriptors::ReceivedHTLC] });
 543                                         amt += htlc.amount_msat / 1000;
 544                                 },
 545                                 &InputMaterial::LocalHTLC { .. } => {
 546                                         dynamic_fee = false;
 547                                 },
 548                                 &InputMaterial::Funding { .. } => {
 549                                         dynamic_fee = false;
 550                                 }
 551                         }
 552                 }
 553                 if dynamic_fee {
 554                         let predicted_weight = (bumped_tx.get_weight() + inputs_witnesses_weight) as u64;
 555                         let mut new_feerate;
 556                         // If old feerate is 0, first iteration of this claim, use normal fee calculation
 557                         if cached_claim_datas.feerate_previous != 0 {
 558                                 if let Some((new_fee, feerate)) = RBF_bump!(amt, cached_claim_datas.feerate_previous, fee_estimator, predicted_weight) {
 559                                         // If new computed fee is superior at the whole claimable amount burn all in fees
 560                                         if new_fee as u64 > amt {
 561                                                 bumped_tx.output[0].value = 0;
 562                                         } else {
 563                                                 bumped_tx.output[0].value = amt - new_fee as u64;
 564                                         }
 565                                         new_feerate = feerate;
 566                                 } else { return None; }
 567                         } else {
 568                                 if subtract_high_prio_fee!(logger, fee_estimator, amt, predicted_weight, new_feerate) {
 569                                         bumped_tx.output[0].value = amt;
 570                                 } else { return None; }
 571                         }
 572                         assert!(new_feerate != 0);
 573
 574                         for (i, (outp, per_outp_material)) in cached_claim_datas.per_input_material.iter().enumerate() {
 575                                 match per_outp_material {
 576                                         &InputMaterial::Revoked { ref per_commitment_point, ref remote_delayed_payment_base_key, ref remote_htlc_base_key, ref per_commitment_key, ref input_descriptor, ref amount, ref htlc, ref on_remote_tx_csv } => {
 577                                                 if let Ok(chan_keys) = TxCreationKeys::new(&self.secp_ctx, &per_commitment_point, remote_delayed_payment_base_key, remote_htlc_base_key, &self.key_storage.pubkeys().revocation_basepoint, &self.key_storage.pubkeys().htlc_basepoint) {
 578
 579                                                         let witness_script = if let Some(ref htlc) = *htlc {
 580                                                                 chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &chan_keys.a_htlc_key, &chan_keys.b_htlc_key, &chan_keys.revocation_key)
 581                                                         } else {
 582                                                                 chan_utils::get_revokeable_redeemscript(&chan_keys.revocation_key, *on_remote_tx_csv, &chan_keys.a_delayed_payment_key)
 583                                                         };
 584
 585                                                         if let Ok(sig) = self.key_storage.sign_justice_transaction(&bumped_tx, i, *amount, &per_commitment_key, htlc, &self.secp_ctx) {
 586                                                                 bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
 587                                                                 bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
 588                                                                 if htlc.is_some() {
 589                                                                         bumped_tx.input[i].witness.push(chan_keys.revocation_key.clone().serialize().to_vec());
 590                                                                 } else {
 591                                                                         bumped_tx.input[i].witness.push(vec!(1));
 592                                                                 }
 593                                                                 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
 594                                                         } else { return None; }
 595                                                         //TODO: panic ?
 596
 597                                                         log_trace!(logger, "Going to broadcast Penalty Transaction {} claiming revoked {} output {} from {} with new feerate {}...", bumped_tx.txid(), if *input_descriptor == InputDescriptors::RevokedOutput { "to_local" } else if *input_descriptor == InputDescriptors::RevokedOfferedHTLC { "offered" } else if *input_descriptor == InputDescriptors::RevokedReceivedHTLC { "received" } else { "" }, outp.vout, outp.txid, new_feerate);
 598                                                 }
 599                                         },
 600                                         &InputMaterial::RemoteHTLC { ref per_commitment_point, ref remote_delayed_payment_base_key, ref remote_htlc_base_key, ref preimage, ref htlc } => {
 601                                                 if let Ok(chan_keys) = TxCreationKeys::new(&self.secp_ctx, &per_commitment_point, remote_delayed_payment_base_key, remote_htlc_base_key, &self.key_storage.pubkeys().revocation_basepoint, &self.key_storage.pubkeys().htlc_basepoint) {
 602                                                         let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &chan_keys.a_htlc_key, &chan_keys.b_htlc_key, &chan_keys.revocation_key);
 603
 604                                                         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
 605                                                         if let Ok(sig) = self.key_storage.sign_remote_htlc_transaction(&bumped_tx, i, &htlc.amount_msat / 1000, &per_commitment_point, htlc, &self.secp_ctx) {
 606                                                                 bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
 607                                                                 bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
 608                                                                 if let &Some(preimage) = preimage {
 609                                                                         bumped_tx.input[i].witness.push(preimage.0.to_vec());
 610                                                                 } else {
 611                                                                         // Due to BIP146 (MINIMALIF) this must be a zero-length element to relay.
 612                                                                         bumped_tx.input[i].witness.push(vec![]);
 613                                                                 }
 614                                                                 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
 615                                                         }
 616                                                         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);
 617                                                 }
 618                                         },
 619                                         _ => unreachable!()
 620                                 }
 621                         }
 622                         log_trace!(logger, "...with timer {}", new_timer.unwrap());
 623                         assert!(predicted_weight >= bumped_tx.get_weight() as u64);
 624                         return Some((new_timer, new_feerate as u32, bumped_tx))
 625                 } else {
 626                         for (_, (outp, per_outp_material)) in cached_claim_datas.per_input_material.iter().enumerate() {
 627                                 match per_outp_material {
 628                                         &InputMaterial::LocalHTLC { ref preimage, ref amount } => {
 629                                                 let htlc_tx = self.get_fully_signed_htlc_tx(outp, preimage);
 630                                                 if let Some(htlc_tx) = htlc_tx {
 631                                                         let feerate = (amount - htlc_tx.output[0].value) * 1000 / htlc_tx.get_weight() as u64;
 632                                                         // Timer set to $NEVER given we can't bump tx without anchor outputs
 633                                                         log_trace!(logger, "Going to broadcast Local HTLC-{} claiming HTLC output {} from {}...", if preimage.is_some() { "Success" } else { "Timeout" }, outp.vout, outp.txid);
 634                                                         return Some((None, feerate as u32, htlc_tx));
 635                                                 }
 636                                                 return None;
 637                                         },
 638                                         &InputMaterial::Funding { ref funding_redeemscript } => {
 639                                                 let signed_tx = self.get_fully_signed_local_tx(funding_redeemscript).unwrap();
 640                                                 // Timer set to $NEVER given we can't bump tx without anchor outputs
 641                                                 log_trace!(logger, "Going to broadcast Local Transaction {} claiming funding output {} from {}...", signed_tx.txid(), outp.vout, outp.txid);
 642                                                 return Some((None, self.local_commitment.as_ref().unwrap().feerate_per_kw, signed_tx));
 643                                         }
 644                                         _ => unreachable!()
 645                                 }
 646                         }
 647                 }
 648                 None
 649         }
 650
 651         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)
 652                 where B::Target: BroadcasterInterface,
 653                       F::Target: FeeEstimator,
 654                                         L::Target: Logger,
 655         {
 656                 log_trace!(logger, "Block at height {} connected with {} claim requests", height, claimable_outpoints.len());
 657                 let mut new_claims = Vec::new();
 658                 let mut aggregated_claim = HashMap::new();
 659                 let mut aggregated_soonest = ::std::u32::MAX;
 660
 661                 // Try to aggregate outputs if their timelock expiration isn't imminent (absolute_timelock
 662                 // <= CLTV_SHARED_CLAIM_BUFFER) and they don't require an immediate nLockTime (aggregable).
 663                 for req in claimable_outpoints {
 664                         // Don't claim a outpoint twice that would be bad for privacy and may uselessly lock a CPFP input for a while
 665                         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 {
 666                                 log_trace!(logger, "Test if outpoint can be aggregated with expiration {} against {}", req.absolute_timelock, height + CLTV_SHARED_CLAIM_BUFFER);
 667                                 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
 668                                         let mut single_input = HashMap::new();
 669                                         single_input.insert(req.outpoint, req.witness_data);
 670                                         new_claims.push((req.absolute_timelock, single_input));
 671                                 } else {
 672                                         aggregated_claim.insert(req.outpoint, req.witness_data);
 673                                         if req.absolute_timelock < aggregated_soonest {
 674                                                 aggregated_soonest = req.absolute_timelock;
 675                                         }
 676                                 }
 677                         }
 678                 }
 679                 new_claims.push((aggregated_soonest, aggregated_claim));
 680
 681                 // Generate claim transactions and track them to bump if necessary at
 682                 // height timer expiration (i.e in how many blocks we're going to take action).
 683                 for (soonest_timelock, claim) in new_claims.drain(..) {
 684                         let mut claim_material = ClaimTxBumpMaterial { height_timer: None, feerate_previous: 0, soonest_timelock, per_input_material: claim };
 685                         if let Some((new_timer, new_feerate, tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator, &*logger) {
 686                                 claim_material.height_timer = new_timer;
 687                                 claim_material.feerate_previous = new_feerate;
 688                                 let txid = tx.txid();
 689                                 for k in claim_material.per_input_material.keys() {
 690                                         log_trace!(logger, "Registering claiming request for {}:{}", k.txid, k.vout);
 691                                         self.claimable_outpoints.insert(k.clone(), (txid, height));
 692                                 }
 693                                 self.pending_claim_requests.insert(txid, claim_material);
 694                                 log_trace!(logger, "Broadcast onchain {}", log_tx!(tx));
 695                                 broadcaster.broadcast_transaction(&tx);
 696                         }
 697                 }
 698
 699                 let mut bump_candidates = HashMap::new();
 700                 for tx in txn_matched {
 701                         // Scan all input to verify is one of the outpoint spent is of interest for us
 702                         let mut claimed_outputs_material = Vec::new();
 703                         for inp in &tx.input {
 704                                 if let Some(first_claim_txid_height) = self.claimable_outpoints.get(&inp.previous_output) {
 705                                         // If outpoint has claim request pending on it...
 706                                         if let Some(claim_material) = self.pending_claim_requests.get_mut(&first_claim_txid_height.0) {
 707                                                 //... we need to verify equality between transaction outpoints and claim request
 708                                                 // outpoints to know if transaction is the original claim or a bumped one issued
 709                                                 // by us.
 710                                                 let mut set_equality = true;
 711                                                 if claim_material.per_input_material.len() != tx.input.len() {
 712                                                         set_equality = false;
 713                                                 } else {
 714                                                         for (claim_inp, tx_inp) in claim_material.per_input_material.keys().zip(tx.input.iter()) {
 715                                                                 if *claim_inp != tx_inp.previous_output {
 716                                                                         set_equality = false;
 717                                                                 }
 718                                                         }
 719                                                 }
 720
 721                                                 macro_rules! clean_claim_request_after_safety_delay {
 722                                                         () => {
 723                                                                 let new_event = OnchainEvent::Claim { claim_request: first_claim_txid_height.0.clone() };
 724                                                                 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
 725                                                                         hash_map::Entry::Occupied(mut entry) => {
 726                                                                                 if !entry.get().contains(&new_event) {
 727                                                                                         entry.get_mut().push(new_event);
 728                                                                                 }
 729                                                                         },
 730                                                                         hash_map::Entry::Vacant(entry) => {
 731                                                                                 entry.insert(vec![new_event]);
 732                                                                         }
 733                                                                 }
 734                                                         }
 735                                                 }
 736
 737                                                 // If this is our transaction (or our counterparty spent all the outputs
 738                                                 // before we could anyway with same inputs order than us), wait for
 739                                                 // ANTI_REORG_DELAY and clean the RBF tracking map.
 740                                                 if set_equality {
 741                                                         clean_claim_request_after_safety_delay!();
 742                                                 } else { // If false, generate new claim request with update outpoint set
 743                                                         let mut at_least_one_drop = false;
 744                                                         for input in tx.input.iter() {
 745                                                                 if let Some(input_material) = claim_material.per_input_material.remove(&input.previous_output) {
 746                                                                         claimed_outputs_material.push((input.previous_output, input_material));
 747                                                                         at_least_one_drop = true;
 748                                                                 }
 749                                                                 // If there are no outpoints left to claim in this request, drop it entirely after ANTI_REORG_DELAY.
 750                                                                 if claim_material.per_input_material.is_empty() {
 751                                                                         clean_claim_request_after_safety_delay!();
 752                                                                 }
 753                                                         }
 754                                                         //TODO: recompute soonest_timelock to avoid wasting a bit on fees
 755                                                         if at_least_one_drop {
 756                                                                 bump_candidates.insert(first_claim_txid_height.0.clone(), claim_material.clone());
 757                                                         }
 758                                                 }
 759                                                 break; //No need to iterate further, either tx is our or their
 760                                         } else {
 761                                                 panic!("Inconsistencies between pending_claim_requests map and claimable_outpoints map");
 762                                         }
 763                                 }
 764                         }
 765                         for (outpoint, input_material) in claimed_outputs_material.drain(..) {
 766                                 let new_event = OnchainEvent::ContentiousOutpoint { outpoint, input_material };
 767                                 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
 768                                         hash_map::Entry::Occupied(mut entry) => {
 769                                                 if !entry.get().contains(&new_event) {
 770                                                         entry.get_mut().push(new_event);
 771                                                 }
 772                                         },
 773                                         hash_map::Entry::Vacant(entry) => {
 774                                                 entry.insert(vec![new_event]);
 775                                         }
 776                                 }
 777                         }
 778                 }
 779
 780                 // After security delay, either our claim tx got enough confs or outpoint is definetely out of reach
 781                 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&height) {
 782                         for ev in events {
 783                                 match ev {
 784                                         OnchainEvent::Claim { claim_request } => {
 785                                                 // We may remove a whole set of claim outpoints here, as these one may have
 786                                                 // been aggregated in a single tx and claimed so atomically
 787                                                 if let Some(bump_material) = self.pending_claim_requests.remove(&claim_request) {
 788                                                         for outpoint in bump_material.per_input_material.keys() {
 789                                                                 self.claimable_outpoints.remove(&outpoint);
 790                                                         }
 791                                                 }
 792                                         },
 793                                         OnchainEvent::ContentiousOutpoint { outpoint, .. } => {
 794                                                 self.claimable_outpoints.remove(&outpoint);
 795                                         }
 796                                 }
 797                         }
 798                 }
 799
 800                 // Check if any pending claim request must be rescheduled
 801                 for (first_claim_txid, ref claim_data) in self.pending_claim_requests.iter() {
 802                         if let Some(h) = claim_data.height_timer {
 803                                 if h == height {
 804                                         bump_candidates.insert(*first_claim_txid, (*claim_data).clone());
 805                                 }
 806                         }
 807                 }
 808
 809                 // Build, bump and rebroadcast tx accordingly
 810                 log_trace!(logger, "Bumping {} candidates", bump_candidates.len());
 811                 for (first_claim_txid, claim_material) in bump_candidates.iter() {
 812                         if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator, &*logger) {
 813                                 log_trace!(logger, "Broadcast onchain {}", log_tx!(bump_tx));
 814                                 broadcaster.broadcast_transaction(&bump_tx);
 815                                 if let Some(claim_material) = self.pending_claim_requests.get_mut(first_claim_txid) {
 816                                         claim_material.height_timer = new_timer;
 817                                         claim_material.feerate_previous = new_feerate;
 818                                 }
 819                         }
 820                 }
 821         }
 822
 823         pub(super) fn block_disconnected<B: Deref, F: Deref, L: Deref>(&mut self, height: u32, broadcaster: B, fee_estimator: F, logger: L)
 824                 where B::Target: BroadcasterInterface,
 825                       F::Target: FeeEstimator,
 826                                         L::Target: Logger,
 827         {
 828                 let mut bump_candidates = HashMap::new();
 829                 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&(height + ANTI_REORG_DELAY - 1)) {
 830                         //- our claim tx on a commitment tx output
 831                         //- resurect outpoint back in its claimable set and regenerate tx
 832                         for ev in events {
 833                                 match ev {
 834                                         OnchainEvent::ContentiousOutpoint { outpoint, input_material } => {
 835                                                 if let Some(ancestor_claimable_txid) = self.claimable_outpoints.get(&outpoint) {
 836                                                         if let Some(claim_material) = self.pending_claim_requests.get_mut(&ancestor_claimable_txid.0) {
 837                                                                 claim_material.per_input_material.insert(outpoint, input_material);
 838                                                                 // Using a HashMap guarantee us than if we have multiple outpoints getting
 839                                                                 // resurrected only one bump claim tx is going to be broadcast
 840                                                                 bump_candidates.insert(ancestor_claimable_txid.clone(), claim_material.clone());
 841                                                         }
 842                                                 }
 843                                         },
 844                                         _ => {},
 845                                 }
 846                         }
 847                 }
 848                 for (_, claim_material) in bump_candidates.iter_mut() {
 849                         if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator, &*logger) {
 850                                 claim_material.height_timer = new_timer;
 851                                 claim_material.feerate_previous = new_feerate;
 852                                 broadcaster.broadcast_transaction(&bump_tx);
 853                         }
 854                 }
 855                 for (ancestor_claim_txid, claim_material) in bump_candidates.drain() {
 856                         self.pending_claim_requests.insert(ancestor_claim_txid.0, claim_material);
 857                 }
 858                 //TODO: if we implement cross-block aggregated claim transaction we need to refresh set of outpoints and regenerate tx but
 859                 // right now if one of the outpoint get disconnected, just erase whole pending claim request.
 860                 let mut remove_request = Vec::new();
 861                 self.claimable_outpoints.retain(|_, ref v|
 862                         if v.1 == height {
 863                         remove_request.push(v.0.clone());
 864                         false
 865                         } else { true });
 866                 for req in remove_request {
 867                         self.pending_claim_requests.remove(&req);
 868                 }
 869         }
 870
 871         pub(super) fn provide_latest_local_tx(&mut self, tx: LocalCommitmentTransaction) -> Result<(), ()> {
 872                 // To prevent any unsafe state discrepancy between offchain and onchain, once local
 873                 // commitment transaction has been signed due to an event (either block height for
 874                 // HTLC-timeout or channel force-closure), don't allow any further update of local
 875                 // commitment transaction view to avoid delivery of revocation secret to counterparty
 876                 // for the aformentionned signed transaction.
 877                 if self.local_htlc_sigs.is_some() || self.prev_local_htlc_sigs.is_some() {
 878                         return Err(());
 879                 }
 880                 self.prev_local_commitment = self.local_commitment.take();
 881                 self.local_commitment = Some(tx);
 882                 Ok(())
 883         }
 884
 885         fn sign_latest_local_htlcs(&mut self) {
 886                 if let Some(ref local_commitment) = self.local_commitment {
 887                         if let Ok(sigs) = self.key_storage.sign_local_commitment_htlc_transactions(local_commitment, &self.secp_ctx) {
 888                                 self.local_htlc_sigs = Some(Vec::new());
 889                                 let ret = self.local_htlc_sigs.as_mut().unwrap();
 890                                 for (htlc_idx, (local_sig, &(ref htlc, _))) in sigs.iter().zip(local_commitment.per_htlc.iter()).enumerate() {
 891                                         if let Some(tx_idx) = htlc.transaction_output_index {
 892                                                 if ret.len() <= tx_idx as usize { ret.resize(tx_idx as usize + 1, None); }
 893                                                 ret[tx_idx as usize] = Some((htlc_idx, local_sig.expect("Did not receive a signature for a non-dust HTLC")));
 894                                         } else {
 895                                                 assert!(local_sig.is_none(), "Received a signature for a dust HTLC");
 896                                         }
 897                                 }
 898                         }
 899                 }
 900         }
 901         fn sign_prev_local_htlcs(&mut self) {
 902                 if let Some(ref local_commitment) = self.prev_local_commitment {
 903                         if let Ok(sigs) = self.key_storage.sign_local_commitment_htlc_transactions(local_commitment, &self.secp_ctx) {
 904                                 self.prev_local_htlc_sigs = Some(Vec::new());
 905                                 let ret = self.prev_local_htlc_sigs.as_mut().unwrap();
 906                                 for (htlc_idx, (local_sig, &(ref htlc, _))) in sigs.iter().zip(local_commitment.per_htlc.iter()).enumerate() {
 907                                         if let Some(tx_idx) = htlc.transaction_output_index {
 908                                                 if ret.len() <= tx_idx as usize { ret.resize(tx_idx as usize + 1, None); }
 909                                                 ret[tx_idx as usize] = Some((htlc_idx, local_sig.expect("Did not receive a signature for a non-dust HTLC")));
 910                                         } else {
 911                                                 assert!(local_sig.is_none(), "Received a signature for a dust HTLC");
 912                                         }
 913                                 }
 914                         }
 915                 }
 916         }
 917
 918         //TODO: getting lastest local transactions should be infaillible and result in us "force-closing the channel", but we may
 919         // have empty local commitment transaction if a ChannelMonitor is asked to force-close just after Channel::get_outbound_funding_created,
 920         // before providing a initial commitment transaction. For outbound channel, init ChannelMonitor at Channel::funding_signed, there is nothing
 921         // to monitor before.
 922         pub(super) fn get_fully_signed_local_tx(&mut self, funding_redeemscript: &Script) -> Option<Transaction> {
 923                 if let Some(ref mut local_commitment) = self.local_commitment {
 924                         match self.key_storage.sign_local_commitment(local_commitment, &self.secp_ctx) {
 925                                 Ok(sig) => Some(local_commitment.add_local_sig(funding_redeemscript, sig)),
 926                                 Err(_) => return None,
 927                         }
 928                 } else {
 929                         None
 930                 }
 931         }
 932
 933         #[cfg(test)]
 934         pub(super) fn get_fully_signed_copy_local_tx(&mut self, funding_redeemscript: &Script) -> Option<Transaction> {
 935                 if let Some(ref mut local_commitment) = self.local_commitment {
 936                         let local_commitment = local_commitment.clone();
 937                         match self.key_storage.sign_local_commitment(&local_commitment, &self.secp_ctx) {
 938                                 Ok(sig) => Some(local_commitment.add_local_sig(funding_redeemscript, sig)),
 939                                 Err(_) => return None,
 940                         }
 941                 } else {
 942                         None
 943                 }
 944         }
 945
 946         pub(super) fn get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
 947                 let mut htlc_tx = None;
 948                 if self.local_commitment.is_some() {
 949                         let commitment_txid = self.local_commitment.as_ref().unwrap().txid();
 950                         if commitment_txid == outp.txid {
 951                                 self.sign_latest_local_htlcs();
 952                                 if let &Some(ref htlc_sigs) = &self.local_htlc_sigs {
 953                                         let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
 954                                         htlc_tx = Some(self.local_commitment.as_ref().unwrap()
 955                                                 .get_signed_htlc_tx(*htlc_idx, htlc_sig, preimage, self.on_local_tx_csv));
 956                                 }
 957                         }
 958                 }
 959                 if self.prev_local_commitment.is_some() {
 960                         let commitment_txid = self.prev_local_commitment.as_ref().unwrap().txid();
 961                         if commitment_txid == outp.txid {
 962                                 self.sign_prev_local_htlcs();
 963                                 if let &Some(ref htlc_sigs) = &self.prev_local_htlc_sigs {
 964                                         let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
 965                                         htlc_tx = Some(self.prev_local_commitment.as_ref().unwrap()
 966                                                 .get_signed_htlc_tx(*htlc_idx, htlc_sig, preimage, self.on_local_tx_csv));
 967                                 }
 968                         }
 969                 }
 970                 htlc_tx
 971         }
 972
 973         #[cfg(test)]
 974         pub(super) fn unsafe_get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
 975                 let latest_had_sigs = self.local_htlc_sigs.is_some();
 976                 let prev_had_sigs = self.prev_local_htlc_sigs.is_some();
 977                 let ret = self.get_fully_signed_htlc_tx(outp, preimage);
 978                 if !latest_had_sigs {
 979                         self.local_htlc_sigs = None;
 980                 }
 981                 if !prev_had_sigs {
 982                         self.prev_local_htlc_sigs = None;
 983                 }
 984                 ret
 985         }
 986 }