_ 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 use bitcoin::secp256k1::key::PublicKey;
  15
  16 use ln::msgs::DecodeError;
  17 use ln::channelmonitor::{ANTI_REORG_DELAY, CLTV_SHARED_CLAIM_BUFFER, InputMaterial, ClaimRequest};
  18 use ln::channelmanager::PaymentPreimage;
  19 use ln::chan_utils;
  20 use ln::chan_utils::{TxCreationKeys, LocalCommitmentTransaction, HTLCOutputInCommitment};
  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::{ReadableArgs, Readable, Writer, Writeable};
  25 use util::byte_utils;
  26
  27 use std::collections::{HashMap, hash_map};
  28 use std::sync::Arc;
  29 use std::cmp;
  30 use std::ops::Deref;
  31
  32 const MAX_ALLOC_SIZE: usize = 64*1024;
  33
  34 /// Upon discovering of some classes of onchain tx by ChannelMonitor, we may have to take actions on it
  35 /// once they mature to enough confirmations (ANTI_REORG_DELAY)
  36 #[derive(Clone, PartialEq)]
  37 enum OnchainEvent {
  38         /// Outpoint under claim process by our own tx, once this one get enough confirmations, we remove it from
  39         /// bump-txn candidate buffer.
  40         Claim {
  41                 claim_request: Txid,
  42         },
  43         /// Claim tx aggregate multiple claimable outpoints. One of the outpoint may be claimed by a remote party tx.
  44         /// In this case, we need to drop the outpoint and regenerate a new claim tx. By safety, we keep tracking
  45         /// the outpoint to be sure to resurect it back to the claim tx if reorgs happen.
  46         ContentiousOutpoint {
  47                 outpoint: BitcoinOutPoint,
  48                 input_material: InputMaterial,
  49         }
  50 }
  51
  52 /// Cache remote basepoint to compute any transaction on
  53 /// remote outputs, either justice or preimage/timeout transactions.
  54 #[derive(PartialEq)]
  55 pub(super) struct RemoteTxCache {
  56         pub(super) remote_delayed_payment_base_key: PublicKey,
  57         pub(super) remote_htlc_base_key: PublicKey,
  58         pub(super) per_htlc: HashMap<Txid, Vec<(HTLCOutputInCommitment)>>
  59 }
  60
  61 /// Higher-level cache structure needed to re-generate bumped claim txn if needed
  62 #[derive(Clone, PartialEq)]
  63 pub struct ClaimTxBumpMaterial {
  64         // At every block tick, used to check if pending claiming tx is taking too
  65         // much time for confirmation and we need to bump it.
  66         height_timer: Option<u32>,
  67         // Tracked in case of reorg to wipe out now-superflous bump material
  68         feerate_previous: u64,
  69         // Soonest timelocks among set of outpoints claimed, used to compute
  70         // a priority of not feerate
  71         soonest_timelock: u32,
  72         // Cache of script, pubkey, sig or key to solve claimable outputs scriptpubkey.
  73         per_input_material: HashMap<BitcoinOutPoint, InputMaterial>,
  74 }
  75
  76 impl Writeable for ClaimTxBumpMaterial  {
  77         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
  78                 self.height_timer.write(writer)?;
  79                 writer.write_all(&byte_utils::be64_to_array(self.feerate_previous))?;
  80                 writer.write_all(&byte_utils::be32_to_array(self.soonest_timelock))?;
  81                 writer.write_all(&byte_utils::be64_to_array(self.per_input_material.len() as u64))?;
  82                 for (outp, tx_material) in self.per_input_material.iter() {
  83                         outp.write(writer)?;
  84                         tx_material.write(writer)?;
  85                 }
  86                 Ok(())
  87         }
  88 }
  89
  90 impl Readable for ClaimTxBumpMaterial {
  91         fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
  92                 let height_timer = Readable::read(reader)?;
  93                 let feerate_previous = Readable::read(reader)?;
  94                 let soonest_timelock = Readable::read(reader)?;
  95                 let per_input_material_len: u64 = Readable::read(reader)?;
  96                 let mut per_input_material = HashMap::with_capacity(cmp::min(per_input_material_len as usize, MAX_ALLOC_SIZE / 128));
  97                 for _ in 0 ..per_input_material_len {
  98                         let outpoint = Readable::read(reader)?;
  99                         let input_material = Readable::read(reader)?;
 100                         per_input_material.insert(outpoint, input_material);
 101                 }
 102                 Ok(Self { height_timer, feerate_previous, soonest_timelock, per_input_material })
 103         }
 104 }
 105
 106 #[derive(PartialEq, Clone, Copy)]
 107 pub(crate) enum InputDescriptors {
 108         RevokedOfferedHTLC,
 109         RevokedReceivedHTLC,
 110         OfferedHTLC,
 111         ReceivedHTLC,
 112         RevokedOutput, // either a revoked to_local output on commitment tx, a revoked HTLC-Timeout output or a revoked HTLC-Success output
 113 }
 114
 115 impl Writeable for InputDescriptors {
 116         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 117                 match self {
 118                         &InputDescriptors::RevokedOfferedHTLC => {
 119                                 writer.write_all(&[0; 1])?;
 120                         },
 121                         &InputDescriptors::RevokedReceivedHTLC => {
 122                                 writer.write_all(&[1; 1])?;
 123                         },
 124                         &InputDescriptors::OfferedHTLC => {
 125                                 writer.write_all(&[2; 1])?;
 126                         },
 127                         &InputDescriptors::ReceivedHTLC => {
 128                                 writer.write_all(&[3; 1])?;
 129                         }
 130                         &InputDescriptors::RevokedOutput => {
 131                                 writer.write_all(&[4; 1])?;
 132                         }
 133                 }
 134                 Ok(())
 135         }
 136 }
 137
 138 impl Readable for InputDescriptors {
 139         fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
 140                 let input_descriptor = match <u8 as Readable>::read(reader)? {
 141                         0 => {
 142                                 InputDescriptors::RevokedOfferedHTLC
 143                         },
 144                         1 => {
 145                                 InputDescriptors::RevokedReceivedHTLC
 146                         },
 147                         2 => {
 148                                 InputDescriptors::OfferedHTLC
 149                         },
 150                         3 => {
 151                                 InputDescriptors::ReceivedHTLC
 152                         },
 153                         4 => {
 154                                 InputDescriptors::RevokedOutput
 155                         }
 156                         _ => return Err(DecodeError::InvalidValue),
 157                 };
 158                 Ok(input_descriptor)
 159         }
 160 }
 161
 162 macro_rules! subtract_high_prio_fee {
 163         ($self: ident, $fee_estimator: expr, $value: expr, $predicted_weight: expr, $used_feerate: expr) => {
 164                 {
 165                         $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority);
 166                         let mut fee = $used_feerate * ($predicted_weight as u64) / 1000;
 167                         if $value <= fee {
 168                                 $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Normal);
 169                                 fee = $used_feerate * ($predicted_weight as u64) / 1000;
 170                                 if $value <= fee {
 171                                         $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background);
 172                                         fee = $used_feerate * ($predicted_weight as u64) / 1000;
 173                                         if $value <= fee {
 174                                                 log_error!($self, "Failed to generate an on-chain punishment tx as even low priority fee ({} sat) was more than the entire claim balance ({} sat)",
 175                                                         fee, $value);
 176                                                 false
 177                                         } else {
 178                                                 log_warn!($self, "Used low priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
 179                                                         $value);
 180                                                 $value -= fee;
 181                                                 true
 182                                         }
 183                                 } else {
 184                                         log_warn!($self, "Used medium priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
 185                                                 $value);
 186                                         $value -= fee;
 187                                         true
 188                                 }
 189                         } else {
 190                                 $value -= fee;
 191                                 true
 192                         }
 193                 }
 194         }
 195 }
 196
 197 impl Readable for Option<Vec<Option<(usize, Signature)>>> {
 198         fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
 199                 match Readable::read(reader)? {
 200                         0u8 => Ok(None),
 201                         1u8 => {
 202                                 let vlen: u64 = Readable::read(reader)?;
 203                                 let mut ret = Vec::with_capacity(cmp::min(vlen as usize, MAX_ALLOC_SIZE / ::std::mem::size_of::<Option<(usize, Signature)>>()));
 204                                 for _ in 0..vlen {
 205                                         ret.push(match Readable::read(reader)? {
 206                                                 0u8 => None,
 207                                                 1u8 => Some((<u64 as Readable>::read(reader)? as usize, Readable::read(reader)?)),
 208                                                 _ => return Err(DecodeError::InvalidValue)
 209                                         });
 210                                 }
 211                                 Ok(Some(ret))
 212                         },
 213                         _ => Err(DecodeError::InvalidValue),
 214                 }
 215         }
 216 }
 217
 218 impl Writeable for Option<Vec<Option<(usize, Signature)>>> {
 219         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 220                 match self {
 221                         &Some(ref vec) => {
 222                                 1u8.write(writer)?;
 223                                 (vec.len() as u64).write(writer)?;
 224                                 for opt in vec.iter() {
 225                                         match opt {
 226                                                 &Some((ref idx, ref sig)) => {
 227                                                         1u8.write(writer)?;
 228                                                         (*idx as u64).write(writer)?;
 229                                                         sig.write(writer)?;
 230                                                 },
 231                                                 &None => 0u8.write(writer)?,
 232                                         }
 233                                 }
 234                         },
 235                         &None => 0u8.write(writer)?,
 236                 }
 237                 Ok(())
 238         }
 239 }
 240
 241
 242 /// OnchainTxHandler receives claiming requests, aggregates them if it's sound, broadcast and
 243 /// do RBF bumping if possible.
 244 pub struct OnchainTxHandler<ChanSigner: ChannelKeys> {
 245         destination_script: Script,
 246         local_commitment: Option<LocalCommitmentTransaction>,
 247         // local_htlc_sigs and prev_local_htlc_sigs are in the order as they appear in the commitment
 248         // transaction outputs (hence the Option<>s inside the Vec). The first usize is the index in
 249         // the set of HTLCs in the LocalCommitmentTransaction (including those which do not appear in
 250         // the commitment transaction).
 251         local_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
 252         prev_local_commitment: Option<LocalCommitmentTransaction>,
 253         prev_local_htlc_sigs: Option<Vec<Option<(usize, Signature)>>>,
 254         local_csv: u16,
 255         remote_tx_cache: RemoteTxCache,
 256         remote_csv: u16,
 257
 258         key_storage: ChanSigner,
 259
 260         // Used to track claiming requests. If claim tx doesn't confirm before height timer expiration we need to bump
 261         // it (RBF or CPFP). If an input has been part of an aggregate tx at first claim try, we need to keep it within
 262         // another bumped aggregate tx to comply with RBF rules. We may have multiple claiming txn in the flight for the
 263         // same set of outpoints. One of the outpoints may be spent by a transaction not issued by us. That's why at
 264         // block connection we scan all inputs and if any of them is among a set of a claiming request we test for set
 265         // equality between spending transaction and claim request. If true, it means transaction was one our claiming one
 266         // after a security delay of 6 blocks we remove pending claim request. If false, it means transaction wasn't and
 267         // we need to regenerate new claim request with reduced set of still-claimable outpoints.
 268         // Key is identifier of the pending claim request, i.e the txid of the initial claiming transaction generated by
 269         // us and is immutable until all outpoint of the claimable set are post-anti-reorg-delay solved.
 270         // Entry is cache of elements need to generate a bumped claiming transaction (see ClaimTxBumpMaterial)
 271         #[cfg(test)] // Used in functional_test to verify sanitization
 272         pub pending_claim_requests: HashMap<Txid, ClaimTxBumpMaterial>,
 273         #[cfg(not(test))]
 274         pending_claim_requests: HashMap<Txid, ClaimTxBumpMaterial>,
 275
 276         // Used to link outpoints claimed in a connected block to a pending claim request.
 277         // Key is outpoint than monitor parsing has detected we have keys/scripts to claim
 278         // Value is (pending claim request identifier, confirmation_block), identifier
 279         // is txid of the initial claiming transaction and is immutable until outpoint is
 280         // post-anti-reorg-delay solved, confirmaiton_block is used to erase entry if
 281         // block with output gets disconnected.
 282         #[cfg(test)] // Used in functional_test to verify sanitization
 283         pub claimable_outpoints: HashMap<BitcoinOutPoint, (Txid, u32)>,
 284         #[cfg(not(test))]
 285         claimable_outpoints: HashMap<BitcoinOutPoint, (Txid, u32)>,
 286
 287         onchain_events_waiting_threshold_conf: HashMap<u32, Vec<OnchainEvent>>,
 288
 289         secp_ctx: Secp256k1<secp256k1::All>,
 290         logger: Arc<Logger>
 291 }
 292
 293 impl<ChanSigner: ChannelKeys + Writeable> OnchainTxHandler<ChanSigner> {
 294         pub(crate) fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 295                 self.destination_script.write(writer)?;
 296                 self.local_commitment.write(writer)?;
 297                 self.local_htlc_sigs.write(writer)?;
 298                 self.prev_local_commitment.write(writer)?;
 299                 self.prev_local_htlc_sigs.write(writer)?;
 300
 301                 self.local_csv.write(writer)?;
 302
 303                 self.remote_tx_cache.remote_delayed_payment_base_key.write(writer)?;
 304                 self.remote_tx_cache.remote_htlc_base_key.write(writer)?;
 305                 writer.write_all(&byte_utils::be64_to_array(self.remote_tx_cache.per_htlc.len() as u64))?;
 306                 for (ref txid, ref htlcs) in self.remote_tx_cache.per_htlc.iter() {
 307                         writer.write_all(&txid[..])?;
 308                         writer.write_all(&byte_utils::be64_to_array(htlcs.len() as u64))?;
 309                         for &ref htlc in htlcs.iter() {
 310                                 htlc.write(writer)?;
 311                         }
 312                 }
 313                 self.remote_csv.write(writer)?;
 314
 315                 self.key_storage.write(writer)?;
 316
 317                 writer.write_all(&byte_utils::be64_to_array(self.pending_claim_requests.len() as u64))?;
 318                 for (ref ancestor_claim_txid, claim_tx_data) in self.pending_claim_requests.iter() {
 319                         ancestor_claim_txid.write(writer)?;
 320                         claim_tx_data.write(writer)?;
 321                 }
 322
 323                 writer.write_all(&byte_utils::be64_to_array(self.claimable_outpoints.len() as u64))?;
 324                 for (ref outp, ref claim_and_height) in self.claimable_outpoints.iter() {
 325                         outp.write(writer)?;
 326                         claim_and_height.0.write(writer)?;
 327                         claim_and_height.1.write(writer)?;
 328                 }
 329
 330                 writer.write_all(&byte_utils::be64_to_array(self.onchain_events_waiting_threshold_conf.len() as u64))?;
 331                 for (ref target, ref events) in self.onchain_events_waiting_threshold_conf.iter() {
 332                         writer.write_all(&byte_utils::be32_to_array(**target))?;
 333                         writer.write_all(&byte_utils::be64_to_array(events.len() as u64))?;
 334                         for ev in events.iter() {
 335                                 match *ev {
 336                                         OnchainEvent::Claim { ref claim_request } => {
 337                                                 writer.write_all(&[0; 1])?;
 338                                                 claim_request.write(writer)?;
 339                                         },
 340                                         OnchainEvent::ContentiousOutpoint { ref outpoint, ref input_material } => {
 341                                                 writer.write_all(&[1; 1])?;
 342                                                 outpoint.write(writer)?;
 343                                                 input_material.write(writer)?;
 344                                         }
 345                                 }
 346                         }
 347                 }
 348                 Ok(())
 349         }
 350 }
 351
 352 impl<ChanSigner: ChannelKeys + Readable> ReadableArgs<Arc<Logger>> for OnchainTxHandler<ChanSigner> {
 353         fn read<R: ::std::io::Read>(reader: &mut R, logger: Arc<Logger>) -> Result<Self, DecodeError> {
 354                 let destination_script = Readable::read(reader)?;
 355
 356                 let local_commitment = Readable::read(reader)?;
 357                 let local_htlc_sigs = Readable::read(reader)?;
 358                 let prev_local_commitment = Readable::read(reader)?;
 359                 let prev_local_htlc_sigs = Readable::read(reader)?;
 360
 361                 let local_csv = Readable::read(reader)?;
 362
 363                 let remote_tx_cache = {
 364                         let remote_delayed_payment_base_key = Readable::read(reader)?;
 365                         let remote_htlc_base_key = Readable::read(reader)?;
 366                         let per_htlc_len: u64 = Readable::read(reader)?;
 367                         let mut per_htlc = HashMap::with_capacity(cmp::min(per_htlc_len as usize, MAX_ALLOC_SIZE / 64));
 368                         for _  in 0..per_htlc_len {
 369                                 let txid: Txid = Readable::read(reader)?;
 370                                 let htlcs_count: u64 = Readable::read(reader)?;
 371                                 let mut htlcs = Vec::with_capacity(cmp::min(htlcs_count as usize, MAX_ALLOC_SIZE / 32));
 372                                 for _ in 0..htlcs_count {
 373                                         let htlc = Readable::read(reader)?;
 374                                         htlcs.push(htlc);
 375                                 }
 376                                 if let Some(_) = per_htlc.insert(txid, htlcs) {
 377                                         return Err(DecodeError::InvalidValue);
 378                                 }
 379                         }
 380                         RemoteTxCache {
 381                                 remote_delayed_payment_base_key,
 382                                 remote_htlc_base_key,
 383                                 per_htlc,
 384                         }
 385                 };
 386                 let remote_csv = Readable::read(reader)?;
 387
 388                 let key_storage = Readable::read(reader)?;
 389
 390                 let pending_claim_requests_len: u64 = Readable::read(reader)?;
 391                 let mut pending_claim_requests = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
 392                 for _ in 0..pending_claim_requests_len {
 393                         pending_claim_requests.insert(Readable::read(reader)?, Readable::read(reader)?);
 394                 }
 395
 396                 let claimable_outpoints_len: u64 = Readable::read(reader)?;
 397                 let mut claimable_outpoints = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
 398                 for _ in 0..claimable_outpoints_len {
 399                         let outpoint = Readable::read(reader)?;
 400                         let ancestor_claim_txid = Readable::read(reader)?;
 401                         let height = Readable::read(reader)?;
 402                         claimable_outpoints.insert(outpoint, (ancestor_claim_txid, height));
 403                 }
 404                 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
 405                 let mut onchain_events_waiting_threshold_conf = HashMap::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
 406                 for _ in 0..waiting_threshold_conf_len {
 407                         let height_target = Readable::read(reader)?;
 408                         let events_len: u64 = Readable::read(reader)?;
 409                         let mut events = Vec::with_capacity(cmp::min(events_len as usize, MAX_ALLOC_SIZE / 128));
 410                         for _ in 0..events_len {
 411                                 let ev = match <u8 as Readable>::read(reader)? {
 412                                         0 => {
 413                                                 let claim_request = Readable::read(reader)?;
 414                                                 OnchainEvent::Claim {
 415                                                         claim_request
 416                                                 }
 417                                         },
 418                                         1 => {
 419                                                 let outpoint = Readable::read(reader)?;
 420                                                 let input_material = Readable::read(reader)?;
 421                                                 OnchainEvent::ContentiousOutpoint {
 422                                                         outpoint,
 423                                                         input_material
 424                                                 }
 425                                         }
 426                                         _ => return Err(DecodeError::InvalidValue),
 427                                 };
 428                                 events.push(ev);
 429                         }
 430                         onchain_events_waiting_threshold_conf.insert(height_target, events);
 431                 }
 432
 433                 Ok(OnchainTxHandler {
 434                         destination_script,
 435                         local_commitment,
 436                         local_htlc_sigs,
 437                         prev_local_commitment,
 438                         prev_local_htlc_sigs,
 439                         local_csv,
 440                         remote_tx_cache,
 441                         remote_csv,
 442                         key_storage,
 443                         claimable_outpoints,
 444                         pending_claim_requests,
 445                         onchain_events_waiting_threshold_conf,
 446                         secp_ctx: Secp256k1::new(),
 447                         logger,
 448                 })
 449         }
 450 }
 451
 452 impl<ChanSigner: ChannelKeys> OnchainTxHandler<ChanSigner> {
 453         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, logger: Arc<Logger>) -> Self {
 454
 455                 let key_storage = keys;
 456
 457                 let remote_tx_cache = RemoteTxCache {
 458                         remote_delayed_payment_base_key,
 459                         remote_htlc_base_key,
 460                         per_htlc: HashMap::new(),
 461                 };
 462
 463                 OnchainTxHandler {
 464                         destination_script,
 465                         local_commitment: None,
 466                         local_htlc_sigs: None,
 467                         prev_local_commitment: None,
 468                         prev_local_htlc_sigs: None,
 469                         local_csv,
 470                         remote_tx_cache,
 471                         remote_csv,
 472                         key_storage,
 473                         pending_claim_requests: HashMap::new(),
 474                         claimable_outpoints: HashMap::new(),
 475                         onchain_events_waiting_threshold_conf: HashMap::new(),
 476
 477                         secp_ctx: Secp256k1::new(),
 478                         logger,
 479                 }
 480         }
 481
 482         pub(super) fn get_witnesses_weight(inputs: &[InputDescriptors]) -> usize {
 483                 let mut tx_weight = 2; // count segwit flags
 484                 for inp in inputs {
 485                         // We use expected weight (and not actual) as signatures and time lock delays may vary
 486                         tx_weight +=  match inp {
 487                                 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
 488                                 &InputDescriptors::RevokedOfferedHTLC => {
 489                                         1 + 1 + 73 + 1 + 33 + 1 + 133
 490                                 },
 491                                 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
 492                                 &InputDescriptors::RevokedReceivedHTLC => {
 493                                         1 + 1 + 73 + 1 + 33 + 1 + 139
 494                                 },
 495                                 // number_of_witness_elements + sig_length + remotehtlc_sig  + preimage_length + preimage + witness_script_length + witness_script
 496                                 &InputDescriptors::OfferedHTLC => {
 497                                         1 + 1 + 73 + 1 + 32 + 1 + 133
 498                                 },
 499                                 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
 500                                 &InputDescriptors::ReceivedHTLC => {
 501                                         1 + 1 + 73 + 1 + 1 + 1 + 139
 502                                 },
 503                                 // number_of_witness_elements + sig_length + revocation_sig + true_length + op_true + witness_script_length + witness_script
 504                                 &InputDescriptors::RevokedOutput => {
 505                                         1 + 1 + 73 + 1 + 1 + 1 + 77
 506                                 },
 507                         };
 508                 }
 509                 tx_weight
 510         }
 511
 512         /// In LN, output claimed are time-sensitive, which means we have to spend them before reaching some timelock expiration. At in-channel
 513         /// 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
 514         /// height than once reached we should generate a new bumped "version" of the claim tx to be sure than we safely claim outputs before
 515         /// than our counterparty can do it too. If timelock expires soon, height timer is going to be scale down in consequence to increase
 516         /// frequency of the bump and so increase our bets of success.
 517         fn get_height_timer(current_height: u32, timelock_expiration: u32) -> u32 {
 518                 if timelock_expiration <= current_height + 3 {
 519                         return current_height + 1
 520                 } else if timelock_expiration - current_height <= 15 {
 521                         return current_height + 3
 522                 }
 523                 current_height + 15
 524         }
 525
 526         /// 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
 527         /// (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.
 528         fn generate_claim_tx<F: Deref>(&mut self, height: u32, cached_claim_datas: &ClaimTxBumpMaterial, fee_estimator: F) -> Option<(Option<u32>, u64, Transaction)>
 529                 where F::Target: FeeEstimator
 530         {
 531                 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
 532                 let mut inputs = Vec::new();
 533                 for outp in cached_claim_datas.per_input_material.keys() {
 534                         log_trace!(self, "Outpoint {}:{}", outp.txid, outp.vout);
 535                         inputs.push(TxIn {
 536                                 previous_output: *outp,
 537                                 script_sig: Script::new(),
 538                                 sequence: 0xfffffffd,
 539                                 witness: Vec::new(),
 540                         });
 541                 }
 542                 let mut bumped_tx = Transaction {
 543                         version: 2,
 544                         lock_time: 0,
 545                         input: inputs,
 546                         output: vec![TxOut {
 547                                 script_pubkey: self.destination_script.clone(),
 548                                 value: 0
 549                         }],
 550                 };
 551
 552                 macro_rules! RBF_bump {
 553                         ($amount: expr, $old_feerate: expr, $fee_estimator: expr, $predicted_weight: expr) => {
 554                                 {
 555                                         let mut used_feerate;
 556                                         // If old feerate inferior to actual one given back by Fee Estimator, use it to compute new fee...
 557                                         let new_fee = if $old_feerate < $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority) {
 558                                                 let mut value = $amount;
 559                                                 if subtract_high_prio_fee!(self, $fee_estimator, value, $predicted_weight, used_feerate) {
 560                                                         // Overflow check is done in subtract_high_prio_fee
 561                                                         $amount - value
 562                                                 } else {
 563                                                         log_trace!(self, "Can't new-estimation bump new claiming tx, amount {} is too small", $amount);
 564                                                         return None;
 565                                                 }
 566                                         // ...else just increase the previous feerate by 25% (because that's a nice number)
 567                                         } else {
 568                                                 let fee = $old_feerate * $predicted_weight / 750;
 569                                                 if $amount <= fee {
 570                                                         log_trace!(self, "Can't 25% bump new claiming tx, amount {} is too small", $amount);
 571                                                         return None;
 572                                                 }
 573                                                 fee
 574                                         };
 575
 576                                         let previous_fee = $old_feerate * $predicted_weight / 1000;
 577                                         let min_relay_fee = MIN_RELAY_FEE_SAT_PER_1000_WEIGHT * $predicted_weight / 1000;
 578                                         // BIP 125 Opt-in Full Replace-by-Fee Signaling
 579                                         //      * 3. The replacement transaction pays an absolute fee of at least the sum paid by the original transactions.
 580                                         //      * 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.
 581                                         let new_fee = if new_fee < previous_fee + min_relay_fee {
 582                                                 new_fee + previous_fee + min_relay_fee - new_fee
 583                                         } else {
 584                                                 new_fee
 585                                         };
 586                                         Some((new_fee, new_fee * 1000 / $predicted_weight))
 587                                 }
 588                         }
 589                 }
 590
 591                 // Compute new height timer to decide when we need to regenerate a new bumped version of the claim tx (if we
 592                 // didn't receive confirmation of it before, or not enough reorg-safe depth on top of it).
 593                 let new_timer = Some(Self::get_height_timer(height, cached_claim_datas.soonest_timelock));
 594                 let mut inputs_witnesses_weight = 0;
 595                 let mut amt = 0;
 596                 let mut dynamic_fee = true;
 597                 for per_outp_material in cached_claim_datas.per_input_material.values() {
 598                         match per_outp_material {
 599                                 &InputMaterial::Revoked { ref input_descriptor, ref amount, .. } => {
 600                                         inputs_witnesses_weight += Self::get_witnesses_weight(&[*input_descriptor]);
 601                                         amt += *amount;
 602                                 },
 603                                 &InputMaterial::RemoteHTLC { ref preimage, ref htlc, .. } => {
 604                                         inputs_witnesses_weight += Self::get_witnesses_weight(if preimage.is_some() { &[InputDescriptors::OfferedHTLC] } else { &[InputDescriptors::ReceivedHTLC] });
 605                                         amt += htlc.amount_msat / 1000;
 606                                 },
 607                                 &InputMaterial::LocalHTLC { .. } => {
 608                                         dynamic_fee = false;
 609                                 },
 610                                 &InputMaterial::Funding { .. } => {
 611                                         dynamic_fee = false;
 612                                 }
 613                         }
 614                 }
 615                 if dynamic_fee {
 616                         let predicted_weight = bumped_tx.get_weight() + inputs_witnesses_weight;
 617                         let mut new_feerate;
 618                         // If old feerate is 0, first iteration of this claim, use normal fee calculation
 619                         if cached_claim_datas.feerate_previous != 0 {
 620                                 if let Some((new_fee, feerate)) = RBF_bump!(amt, cached_claim_datas.feerate_previous, fee_estimator, predicted_weight as u64) {
 621                                         // If new computed fee is superior at the whole claimable amount burn all in fees
 622                                         if new_fee > amt {
 623                                                 bumped_tx.output[0].value = 0;
 624                                         } else {
 625                                                 bumped_tx.output[0].value = amt - new_fee;
 626                                         }
 627                                         new_feerate = feerate;
 628                                 } else { return None; }
 629                         } else {
 630                                 if subtract_high_prio_fee!(self, fee_estimator, amt, predicted_weight, new_feerate) {
 631                                         bumped_tx.output[0].value = amt;
 632                                 } else { return None; }
 633                         }
 634                         assert!(new_feerate != 0);
 635
 636                         for (i, (outp, per_outp_material)) in cached_claim_datas.per_input_material.iter().enumerate() {
 637                                 match per_outp_material {
 638                                         &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 } => {
 639                                                 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) {
 640
 641                                                         let witness_script = if let Some(ref htlc) = *htlc {
 642                                                                 chan_utils::get_htlc_redeemscript_with_explicit_keys(&htlc, &chan_keys.a_htlc_key, &chan_keys.b_htlc_key, &chan_keys.revocation_key)
 643                                                         } else {
 644                                                                 chan_utils::get_revokeable_redeemscript(&chan_keys.revocation_key, self.remote_csv, &chan_keys.a_delayed_payment_key)
 645                                                         };
 646
 647                                                         if let Ok(sig) = self.key_storage.sign_justice_transaction(&bumped_tx, i, &witness_script, *amount, &per_commitment_key, &chan_keys.revocation_key, htlc.is_some(),  &self.secp_ctx) {
 648                                                                 bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
 649                                                                 bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
 650                                                                 if htlc.is_some() {
 651                                                                         bumped_tx.input[i].witness.push(chan_keys.revocation_key.clone().serialize().to_vec());
 652                                                                 } else {
 653                                                                         bumped_tx.input[i].witness.push(vec!(1));
 654                                                                 }
 655                                                                 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
 656                                                         } else { return None; }
 657                                                         //TODO: panic ?
 658
 659                                                         log_trace!(self, "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);
 660                                                 }
 661                                         },
 662                                         &InputMaterial::RemoteHTLC { ref per_commitment_point, ref remote_delayed_payment_base_key, ref remote_htlc_base_key, ref preimage, ref htlc } => {
 663                                                 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) {
 664                                                         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);
 665
 666                                                         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
 667                                                         if let Ok(sig) = self.key_storage.sign_remote_htlc_transaction(&bumped_tx, i, &witness_script, htlc.amount_msat / 1000, &per_commitment_point, preimage, &self.secp_ctx) {
 668                                                                 bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
 669                                                                 bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
 670                                                                 if let &Some(preimage) = preimage {
 671                                                                         bumped_tx.input[i].witness.push(preimage.0.to_vec());
 672                                                                 } else {
 673                                                                         // Due to BIP146 (MINIMALIF) this must be a zero-length element to relay.
 674                                                                         bumped_tx.input[i].witness.push(vec![]);
 675                                                                 }
 676                                                                 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
 677                                                         }
 678                                                         log_trace!(self, "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);
 679                                                 }
 680                                         },
 681                                         _ => unreachable!()
 682                                 }
 683                         }
 684                         log_trace!(self, "...with timer {}", new_timer.unwrap());
 685                         assert!(predicted_weight >= bumped_tx.get_weight());
 686                         return Some((new_timer, new_feerate, bumped_tx))
 687                 } else {
 688                         for (_, (outp, per_outp_material)) in cached_claim_datas.per_input_material.iter().enumerate() {
 689                                 match per_outp_material {
 690                                         &InputMaterial::LocalHTLC { ref preimage, ref amount } => {
 691                                                 let htlc_tx = self.get_fully_signed_htlc_tx(outp, preimage);
 692                                                 if let Some(htlc_tx) = htlc_tx {
 693                                                         let feerate = (amount - htlc_tx.output[0].value) * 1000 / htlc_tx.get_weight() as u64;
 694                                                         // Timer set to $NEVER given we can't bump tx without anchor outputs
 695                                                         log_trace!(self, "Going to broadcast Local HTLC-{} claiming HTLC output {} from {}...", if preimage.is_some() { "Success" } else { "Timeout" }, outp.vout, outp.txid);
 696                                                         return Some((None, feerate, htlc_tx));
 697                                                 }
 698                                                 return None;
 699                                         },
 700                                         &InputMaterial::Funding { ref funding_redeemscript } => {
 701                                                 let signed_tx = self.get_fully_signed_local_tx(funding_redeemscript).unwrap();
 702                                                 // Timer set to $NEVER given we can't bump tx without anchor outputs
 703                                                 log_trace!(self, "Going to broadcast Local Transaction {} claiming funding output {} from {}...", signed_tx.txid(), outp.vout, outp.txid);
 704                                                 return Some((None, self.local_commitment.as_ref().unwrap().feerate_per_kw, signed_tx));
 705                                         }
 706                                         _ => unreachable!()
 707                                 }
 708                         }
 709                 }
 710                 None
 711         }
 712
 713         pub(super) fn block_connected<B: Deref, F: Deref>(&mut self, txn_matched: &[&Transaction], claimable_outpoints: Vec<ClaimRequest>, height: u32, broadcaster: B, fee_estimator: F)
 714                 where B::Target: BroadcasterInterface,
 715                       F::Target: FeeEstimator
 716         {
 717                 log_trace!(self, "Block at height {} connected with {} claim requests", height, claimable_outpoints.len());
 718                 let mut new_claims = Vec::new();
 719                 let mut aggregated_claim = HashMap::new();
 720                 let mut aggregated_soonest = ::std::u32::MAX;
 721
 722                 // Try to aggregate outputs if their timelock expiration isn't imminent (absolute_timelock
 723                 // <= CLTV_SHARED_CLAIM_BUFFER) and they don't require an immediate nLockTime (aggregable).
 724                 for req in claimable_outpoints {
 725                         // Don't claim a outpoint twice that would be bad for privacy and may uselessly lock a CPFP input for a while
 726                         if let Some(_) = self.claimable_outpoints.get(&req.outpoint) { log_trace!(self, "Bouncing off outpoint {}:{}, already registered its claiming request", req.outpoint.txid, req.outpoint.vout); } else {
 727                                 log_trace!(self, "Test if outpoint can be aggregated with expiration {} against {}", req.absolute_timelock, height + CLTV_SHARED_CLAIM_BUFFER);
 728                                 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
 729                                         let mut single_input = HashMap::new();
 730                                         single_input.insert(req.outpoint, req.witness_data);
 731                                         new_claims.push((req.absolute_timelock, single_input));
 732                                 } else {
 733                                         aggregated_claim.insert(req.outpoint, req.witness_data);
 734                                         if req.absolute_timelock < aggregated_soonest {
 735                                                 aggregated_soonest = req.absolute_timelock;
 736                                         }
 737                                 }
 738                         }
 739                 }
 740                 new_claims.push((aggregated_soonest, aggregated_claim));
 741
 742                 // Generate claim transactions and track them to bump if necessary at
 743                 // height timer expiration (i.e in how many blocks we're going to take action).
 744                 for (soonest_timelock, claim) in new_claims.drain(..) {
 745                         let mut claim_material = ClaimTxBumpMaterial { height_timer: None, feerate_previous: 0, soonest_timelock, per_input_material: claim };
 746                         if let Some((new_timer, new_feerate, tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator) {
 747                                 claim_material.height_timer = new_timer;
 748                                 claim_material.feerate_previous = new_feerate;
 749                                 let txid = tx.txid();
 750                                 for k in claim_material.per_input_material.keys() {
 751                                         log_trace!(self, "Registering claiming request for {}:{}", k.txid, k.vout);
 752                                         self.claimable_outpoints.insert(k.clone(), (txid, height));
 753                                 }
 754                                 self.pending_claim_requests.insert(txid, claim_material);
 755                                 log_trace!(self, "Broadcast onchain {}", log_tx!(tx));
 756                                 broadcaster.broadcast_transaction(&tx);
 757                         }
 758                 }
 759
 760                 let mut bump_candidates = HashMap::new();
 761                 for tx in txn_matched {
 762                         // Scan all input to verify is one of the outpoint spent is of interest for us
 763                         let mut claimed_outputs_material = Vec::new();
 764                         for inp in &tx.input {
 765                                 if let Some(first_claim_txid_height) = self.claimable_outpoints.get(&inp.previous_output) {
 766                                         // If outpoint has claim request pending on it...
 767                                         if let Some(claim_material) = self.pending_claim_requests.get_mut(&first_claim_txid_height.0) {
 768                                                 //... we need to verify equality between transaction outpoints and claim request
 769                                                 // outpoints to know if transaction is the original claim or a bumped one issued
 770                                                 // by us.
 771                                                 let mut set_equality = true;
 772                                                 if claim_material.per_input_material.len() != tx.input.len() {
 773                                                         set_equality = false;
 774                                                 } else {
 775                                                         for (claim_inp, tx_inp) in claim_material.per_input_material.keys().zip(tx.input.iter()) {
 776                                                                 if *claim_inp != tx_inp.previous_output {
 777                                                                         set_equality = false;
 778                                                                 }
 779                                                         }
 780                                                 }
 781
 782                                                 macro_rules! clean_claim_request_after_safety_delay {
 783                                                         () => {
 784                                                                 let new_event = OnchainEvent::Claim { claim_request: first_claim_txid_height.0.clone() };
 785                                                                 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
 786                                                                         hash_map::Entry::Occupied(mut entry) => {
 787                                                                                 if !entry.get().contains(&new_event) {
 788                                                                                         entry.get_mut().push(new_event);
 789                                                                                 }
 790                                                                         },
 791                                                                         hash_map::Entry::Vacant(entry) => {
 792                                                                                 entry.insert(vec![new_event]);
 793                                                                         }
 794                                                                 }
 795                                                         }
 796                                                 }
 797
 798                                                 // If this is our transaction (or our counterparty spent all the outputs
 799                                                 // before we could anyway with same inputs order than us), wait for
 800                                                 // ANTI_REORG_DELAY and clean the RBF tracking map.
 801                                                 if set_equality {
 802                                                         clean_claim_request_after_safety_delay!();
 803                                                 } else { // If false, generate new claim request with update outpoint set
 804                                                         let mut at_least_one_drop = false;
 805                                                         for input in tx.input.iter() {
 806                                                                 if let Some(input_material) = claim_material.per_input_material.remove(&input.previous_output) {
 807                                                                         claimed_outputs_material.push((input.previous_output, input_material));
 808                                                                         at_least_one_drop = true;
 809                                                                 }
 810                                                                 // If there are no outpoints left to claim in this request, drop it entirely after ANTI_REORG_DELAY.
 811                                                                 if claim_material.per_input_material.is_empty() {
 812                                                                         clean_claim_request_after_safety_delay!();
 813                                                                 }
 814                                                         }
 815                                                         //TODO: recompute soonest_timelock to avoid wasting a bit on fees
 816                                                         if at_least_one_drop {
 817                                                                 bump_candidates.insert(first_claim_txid_height.0.clone(), claim_material.clone());
 818                                                         }
 819                                                 }
 820                                                 break; //No need to iterate further, either tx is our or their
 821                                         } else {
 822                                                 panic!("Inconsistencies between pending_claim_requests map and claimable_outpoints map");
 823                                         }
 824                                 }
 825                         }
 826                         for (outpoint, input_material) in claimed_outputs_material.drain(..) {
 827                                 let new_event = OnchainEvent::ContentiousOutpoint { outpoint, input_material };
 828                                 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
 829                                         hash_map::Entry::Occupied(mut entry) => {
 830                                                 if !entry.get().contains(&new_event) {
 831                                                         entry.get_mut().push(new_event);
 832                                                 }
 833                                         },
 834                                         hash_map::Entry::Vacant(entry) => {
 835                                                 entry.insert(vec![new_event]);
 836                                         }
 837                                 }
 838                         }
 839                 }
 840
 841                 // After security delay, either our claim tx got enough confs or outpoint is definetely out of reach
 842                 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&height) {
 843                         for ev in events {
 844                                 match ev {
 845                                         OnchainEvent::Claim { claim_request } => {
 846                                                 // We may remove a whole set of claim outpoints here, as these one may have
 847                                                 // been aggregated in a single tx and claimed so atomically
 848                                                 if let Some(bump_material) = self.pending_claim_requests.remove(&claim_request) {
 849                                                         for outpoint in bump_material.per_input_material.keys() {
 850                                                                 self.claimable_outpoints.remove(&outpoint);
 851                                                         }
 852                                                 }
 853                                         },
 854                                         OnchainEvent::ContentiousOutpoint { outpoint, .. } => {
 855                                                 self.claimable_outpoints.remove(&outpoint);
 856                                         }
 857                                 }
 858                         }
 859                 }
 860
 861                 // Check if any pending claim request must be rescheduled
 862                 for (first_claim_txid, ref claim_data) in self.pending_claim_requests.iter() {
 863                         if let Some(h) = claim_data.height_timer {
 864                                 if h == height {
 865                                         bump_candidates.insert(*first_claim_txid, (*claim_data).clone());
 866                                 }
 867                         }
 868                 }
 869
 870                 // Build, bump and rebroadcast tx accordingly
 871                 log_trace!(self, "Bumping {} candidates", bump_candidates.len());
 872                 for (first_claim_txid, claim_material) in bump_candidates.iter() {
 873                         if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator) {
 874                                 log_trace!(self, "Broadcast onchain {}", log_tx!(bump_tx));
 875                                 broadcaster.broadcast_transaction(&bump_tx);
 876                                 if let Some(claim_material) = self.pending_claim_requests.get_mut(first_claim_txid) {
 877                                         claim_material.height_timer = new_timer;
 878                                         claim_material.feerate_previous = new_feerate;
 879                                 }
 880                         }
 881                 }
 882         }
 883
 884         pub(super) fn block_disconnected<B: Deref, F: Deref>(&mut self, height: u32, broadcaster: B, fee_estimator: F)
 885                 where B::Target: BroadcasterInterface,
 886                       F::Target: FeeEstimator
 887         {
 888                 let mut bump_candidates = HashMap::new();
 889                 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&(height + ANTI_REORG_DELAY - 1)) {
 890                         //- our claim tx on a commitment tx output
 891                         //- resurect outpoint back in its claimable set and regenerate tx
 892                         for ev in events {
 893                                 match ev {
 894                                         OnchainEvent::ContentiousOutpoint { outpoint, input_material } => {
 895                                                 if let Some(ancestor_claimable_txid) = self.claimable_outpoints.get(&outpoint) {
 896                                                         if let Some(claim_material) = self.pending_claim_requests.get_mut(&ancestor_claimable_txid.0) {
 897                                                                 claim_material.per_input_material.insert(outpoint, input_material);
 898                                                                 // Using a HashMap guarantee us than if we have multiple outpoints getting
 899                                                                 // resurrected only one bump claim tx is going to be broadcast
 900                                                                 bump_candidates.insert(ancestor_claimable_txid.clone(), claim_material.clone());
 901                                                         }
 902                                                 }
 903                                         },
 904                                         _ => {},
 905                                 }
 906                         }
 907                 }
 908                 for (_, claim_material) in bump_candidates.iter_mut() {
 909                         if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator) {
 910                                 claim_material.height_timer = new_timer;
 911                                 claim_material.feerate_previous = new_feerate;
 912                                 broadcaster.broadcast_transaction(&bump_tx);
 913                         }
 914                 }
 915                 for (ancestor_claim_txid, claim_material) in bump_candidates.drain() {
 916                         self.pending_claim_requests.insert(ancestor_claim_txid.0, claim_material);
 917                 }
 918                 //TODO: if we implement cross-block aggregated claim transaction we need to refresh set of outpoints and regenerate tx but
 919                 // right now if one of the outpoint get disconnected, just erase whole pending claim request.
 920                 let mut remove_request = Vec::new();
 921                 self.claimable_outpoints.retain(|_, ref v|
 922                         if v.1 == height {
 923                         remove_request.push(v.0.clone());
 924                         false
 925                         } else { true });
 926                 for req in remove_request {
 927                         self.pending_claim_requests.remove(&req);
 928                 }
 929         }
 930
 931         pub(super) fn provide_latest_local_tx(&mut self, tx: LocalCommitmentTransaction) -> Result<(), ()> {
 932                 // To prevent any unsafe state discrepancy between offchain and onchain, once local
 933                 // commitment transaction has been signed due to an event (either block height for
 934                 // HTLC-timeout or channel force-closure), don't allow any further update of local
 935                 // commitment transaction view to avoid delivery of revocation secret to counterparty
 936                 // for the aformentionned signed transaction.
 937                 if self.local_htlc_sigs.is_some() || self.prev_local_htlc_sigs.is_some() {
 938                         return Err(());
 939                 }
 940                 self.prev_local_commitment = self.local_commitment.take();
 941                 self.local_commitment = Some(tx);
 942                 Ok(())
 943         }
 944
 945         fn sign_latest_local_htlcs(&mut self) {
 946                 if let Some(ref local_commitment) = self.local_commitment {
 947                         if let Ok(sigs) = self.key_storage.sign_local_commitment_htlc_transactions(local_commitment, self.local_csv, &self.secp_ctx) {
 948                                 self.local_htlc_sigs = Some(Vec::new());
 949                                 let ret = self.local_htlc_sigs.as_mut().unwrap();
 950                                 for (htlc_idx, (local_sig, &(ref htlc, _))) in sigs.iter().zip(local_commitment.per_htlc.iter()).enumerate() {
 951                                         if let Some(tx_idx) = htlc.transaction_output_index {
 952                                                 if ret.len() <= tx_idx as usize { ret.resize(tx_idx as usize + 1, None); }
 953                                                 ret[tx_idx as usize] = Some((htlc_idx, local_sig.expect("Did not receive a signature for a non-dust HTLC")));
 954                                         } else {
 955                                                 assert!(local_sig.is_none(), "Received a signature for a dust HTLC");
 956                                         }
 957                                 }
 958                         }
 959                 }
 960         }
 961         fn sign_prev_local_htlcs(&mut self) {
 962                 if let Some(ref local_commitment) = self.prev_local_commitment {
 963                         if let Ok(sigs) = self.key_storage.sign_local_commitment_htlc_transactions(local_commitment, self.local_csv, &self.secp_ctx) {
 964                                 self.prev_local_htlc_sigs = Some(Vec::new());
 965                                 let ret = self.prev_local_htlc_sigs.as_mut().unwrap();
 966                                 for (htlc_idx, (local_sig, &(ref htlc, _))) in sigs.iter().zip(local_commitment.per_htlc.iter()).enumerate() {
 967                                         if let Some(tx_idx) = htlc.transaction_output_index {
 968                                                 if ret.len() <= tx_idx as usize { ret.resize(tx_idx as usize + 1, None); }
 969                                                 ret[tx_idx as usize] = Some((htlc_idx, local_sig.expect("Did not receive a signature for a non-dust HTLC")));
 970                                         } else {
 971                                                 assert!(local_sig.is_none(), "Received a signature for a dust HTLC");
 972                                         }
 973                                 }
 974                         }
 975                 }
 976         }
 977
 978         //TODO: getting lastest local transactions should be infaillible and result in us "force-closing the channel", but we may
 979         // have empty local commitment transaction if a ChannelMonitor is asked to force-close just after Channel::get_outbound_funding_created,
 980         // before providing a initial commitment transaction. For outbound channel, init ChannelMonitor at Channel::funding_signed, there is nothing
 981         // to monitor before.
 982         pub(super) fn get_fully_signed_local_tx(&mut self, funding_redeemscript: &Script) -> Option<Transaction> {
 983                 if let Some(ref mut local_commitment) = self.local_commitment {
 984                         match self.key_storage.sign_local_commitment(local_commitment, &self.secp_ctx) {
 985                                 Ok(sig) => Some(local_commitment.add_local_sig(funding_redeemscript, sig)),
 986                                 Err(_) => return None,
 987                         }
 988                 } else {
 989                         None
 990                 }
 991         }
 992
 993         pub(super) fn provide_latest_remote_tx(&mut self, commitment_txid: Txid, htlcs: Vec<HTLCOutputInCommitment>) {
 994                 self.remote_tx_cache.per_htlc.insert(commitment_txid, htlcs);
 995         }
 996
 997         #[cfg(test)]
 998         pub(super) fn get_fully_signed_copy_local_tx(&mut self, funding_redeemscript: &Script) -> Option<Transaction> {
 999                 if let Some(ref mut local_commitment) = self.local_commitment {
1000                         let local_commitment = local_commitment.clone();
1001                         match self.key_storage.sign_local_commitment(&local_commitment, &self.secp_ctx) {
1002                                 Ok(sig) => Some(local_commitment.add_local_sig(funding_redeemscript, sig)),
1003                                 Err(_) => return None,
1004                         }
1005                 } else {
1006                         None
1007                 }
1008         }
1009
1010         pub(super) fn get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
1011                 let mut htlc_tx = None;
1012                 if self.local_commitment.is_some() {
1013                         let commitment_txid = self.local_commitment.as_ref().unwrap().txid();
1014                         if commitment_txid == outp.txid {
1015                                 self.sign_latest_local_htlcs();
1016                                 if let &Some(ref htlc_sigs) = &self.local_htlc_sigs {
1017                                         let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
1018                                         htlc_tx = Some(self.local_commitment.as_ref().unwrap()
1019                                                 .get_signed_htlc_tx(*htlc_idx, htlc_sig, preimage, self.local_csv));
1020                                 }
1021                         }
1022                 }
1023                 if self.prev_local_commitment.is_some() {
1024                         let commitment_txid = self.prev_local_commitment.as_ref().unwrap().txid();
1025                         if commitment_txid == outp.txid {
1026                                 self.sign_prev_local_htlcs();
1027                                 if let &Some(ref htlc_sigs) = &self.prev_local_htlc_sigs {
1028                                         let &(ref htlc_idx, ref htlc_sig) = htlc_sigs[outp.vout as usize].as_ref().unwrap();
1029                                         htlc_tx = Some(self.prev_local_commitment.as_ref().unwrap()
1030                                                 .get_signed_htlc_tx(*htlc_idx, htlc_sig, preimage, self.local_csv));
1031                                 }
1032                         }
1033                 }
1034                 htlc_tx
1035         }
1036
1037         #[cfg(test)]
1038         pub(super) fn unsafe_get_fully_signed_htlc_tx(&mut self, outp: &::bitcoin::OutPoint, preimage: &Option<PaymentPreimage>) -> Option<Transaction> {
1039                 let latest_had_sigs = self.local_htlc_sigs.is_some();
1040                 let prev_had_sigs = self.prev_local_htlc_sigs.is_some();
1041                 let ret = self.get_fully_signed_htlc_tx(outp, preimage);
1042                 if !latest_had_sigs {
1043                         self.local_htlc_sigs = None;
1044                 }
1045                 if !prev_had_sigs {
1046                         self.prev_local_htlc_sigs = None;
1047                 }
1048                 ret
1049         }
1050 }