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

   1 //! The logic to build claims and bump in-flight transactions until confirmations.
   2 //!
   3 //! OnchainTxHandler objetcs are fully-part of ChannelMonitor and encapsulates all
   4 //! building, tracking, bumping and notifications functions.
   5
   6 use bitcoin::blockdata::transaction::{Transaction, TxIn, TxOut, SigHashType};
   7 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
   8 use bitcoin::blockdata::script::Script;
   9 use bitcoin::util::bip143;
  10
  11 use bitcoin_hashes::sha256d::Hash as Sha256dHash;
  12
  13 use secp256k1::Secp256k1;
  14 use secp256k1;
  15
  16 use ln::msgs::DecodeError;
  17 use ln::channelmonitor::{ANTI_REORG_DELAY, CLTV_SHARED_CLAIM_BUFFER, InputMaterial, ClaimRequest};
  18 use ln::chan_utils::{HTLCType, LocalCommitmentTransaction};
  19 use chain::chaininterface::{FeeEstimator, BroadcasterInterface, ConfirmationTarget, MIN_RELAY_FEE_SAT_PER_1000_WEIGHT};
  20 use chain::keysinterface::ChannelKeys;
  21 use util::logger::Logger;
  22 use util::ser::{ReadableArgs, Readable, Writer, Writeable};
  23 use util::byte_utils;
  24
  25 use std::collections::{HashMap, hash_map, HashSet};
  26 use std::sync::Arc;
  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: Sha256dHash,
  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: u32,
  56         // Tracked in case of reorg to wipe out now-superflous bump material
  57         feerate_previous: u64,
  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                 writer.write_all(&byte_utils::be32_to_array(self.height_timer))?;
  68                 writer.write_all(&byte_utils::be64_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)]
  96 pub(super) 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 macro_rules! subtract_high_prio_fee {
 105         ($self: ident, $fee_estimator: expr, $value: expr, $predicted_weight: expr, $used_feerate: expr) => {
 106                 {
 107                         $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority);
 108                         let mut fee = $used_feerate * ($predicted_weight as u64) / 1000;
 109                         if $value <= fee {
 110                                 $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Normal);
 111                                 fee = $used_feerate * ($predicted_weight as u64) / 1000;
 112                                 if $value <= fee {
 113                                         $used_feerate = $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::Background);
 114                                         fee = $used_feerate * ($predicted_weight as u64) / 1000;
 115                                         if $value <= fee {
 116                                                 log_error!($self, "Failed to generate an on-chain punishment tx as even low priority fee ({} sat) was more than the entire claim balance ({} sat)",
 117                                                         fee, $value);
 118                                                 false
 119                                         } else {
 120                                                 log_warn!($self, "Used low priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
 121                                                         $value);
 122                                                 $value -= fee;
 123                                                 true
 124                                         }
 125                                 } else {
 126                                         log_warn!($self, "Used medium priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
 127                                                 $value);
 128                                         $value -= fee;
 129                                         true
 130                                 }
 131                         } else {
 132                                 $value -= fee;
 133                                 true
 134                         }
 135                 }
 136         }
 137 }
 138
 139
 140 /// OnchainTxHandler receives claiming requests, aggregates them if it's sound, broadcast and
 141 /// do RBF bumping if possible.
 142 pub struct OnchainTxHandler<ChanSigner: ChannelKeys> {
 143         destination_script: Script,
 144         funding_redeemscript: Script,
 145         local_commitment: Option<LocalCommitmentTransaction>,
 146         prev_local_commitment: Option<LocalCommitmentTransaction>,
 147
 148         key_storage: ChanSigner,
 149
 150         // Used to track claiming requests. If claim tx doesn't confirm before height timer expiration we need to bump
 151         // it (RBF or CPFP). If an input has been part of an aggregate tx at first claim try, we need to keep it within
 152         // another bumped aggregate tx to comply with RBF rules. We may have multiple claiming txn in the flight for the
 153         // same set of outpoints. One of the outpoints may be spent by a transaction not issued by us. That's why at
 154         // block connection we scan all inputs and if any of them is among a set of a claiming request we test for set
 155         // equality between spending transaction and claim request. If true, it means transaction was one our claiming one
 156         // after a security delay of 6 blocks we remove pending claim request. If false, it means transaction wasn't and
 157         // we need to regenerate new claim request with reduced set of still-claimable outpoints.
 158         // Key is identifier of the pending claim request, i.e the txid of the initial claiming transaction generated by
 159         // us and is immutable until all outpoint of the claimable set are post-anti-reorg-delay solved.
 160         // Entry is cache of elements need to generate a bumped claiming transaction (see ClaimTxBumpMaterial)
 161         #[cfg(test)] // Used in functional_test to verify sanitization
 162         pub pending_claim_requests: HashMap<Sha256dHash, ClaimTxBumpMaterial>,
 163         #[cfg(not(test))]
 164         pending_claim_requests: HashMap<Sha256dHash, ClaimTxBumpMaterial>,
 165
 166         // Used to link outpoints claimed in a connected block to a pending claim request.
 167         // Key is outpoint than monitor parsing has detected we have keys/scripts to claim
 168         // Value is (pending claim request identifier, confirmation_block), identifier
 169         // is txid of the initial claiming transaction and is immutable until outpoint is
 170         // post-anti-reorg-delay solved, confirmaiton_block is used to erase entry if
 171         // block with output gets disconnected.
 172         #[cfg(test)] // Used in functional_test to verify sanitization
 173         pub claimable_outpoints: HashMap<BitcoinOutPoint, (Sha256dHash, u32)>,
 174         #[cfg(not(test))]
 175         claimable_outpoints: HashMap<BitcoinOutPoint, (Sha256dHash, u32)>,
 176
 177         onchain_events_waiting_threshold_conf: HashMap<u32, Vec<OnchainEvent>>,
 178
 179         secp_ctx: Secp256k1<secp256k1::All>,
 180         logger: Arc<Logger>
 181 }
 182
 183 impl<ChanSigner: ChannelKeys + Writeable> OnchainTxHandler<ChanSigner> {
 184         pub(crate) fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
 185                 self.destination_script.write(writer)?;
 186                 self.funding_redeemscript.write(writer)?;
 187                 self.local_commitment.write(writer)?;
 188                 self.prev_local_commitment.write(writer)?;
 189
 190                 self.key_storage.write(writer)?;
 191
 192                 writer.write_all(&byte_utils::be64_to_array(self.pending_claim_requests.len() as u64))?;
 193                 for (ref ancestor_claim_txid, claim_tx_data) in self.pending_claim_requests.iter() {
 194                         ancestor_claim_txid.write(writer)?;
 195                         claim_tx_data.write(writer)?;
 196                 }
 197
 198                 writer.write_all(&byte_utils::be64_to_array(self.claimable_outpoints.len() as u64))?;
 199                 for (ref outp, ref claim_and_height) in self.claimable_outpoints.iter() {
 200                         outp.write(writer)?;
 201                         claim_and_height.0.write(writer)?;
 202                         claim_and_height.1.write(writer)?;
 203                 }
 204
 205                 writer.write_all(&byte_utils::be64_to_array(self.onchain_events_waiting_threshold_conf.len() as u64))?;
 206                 for (ref target, ref events) in self.onchain_events_waiting_threshold_conf.iter() {
 207                         writer.write_all(&byte_utils::be32_to_array(**target))?;
 208                         writer.write_all(&byte_utils::be64_to_array(events.len() as u64))?;
 209                         for ev in events.iter() {
 210                                 match *ev {
 211                                         OnchainEvent::Claim { ref claim_request } => {
 212                                                 writer.write_all(&[0; 1])?;
 213                                                 claim_request.write(writer)?;
 214                                         },
 215                                         OnchainEvent::ContentiousOutpoint { ref outpoint, ref input_material } => {
 216                                                 writer.write_all(&[1; 1])?;
 217                                                 outpoint.write(writer)?;
 218                                                 input_material.write(writer)?;
 219                                         }
 220                                 }
 221                         }
 222                 }
 223                 Ok(())
 224         }
 225 }
 226
 227 impl<ChanSigner: ChannelKeys + Readable> ReadableArgs<Arc<Logger>> for OnchainTxHandler<ChanSigner> {
 228         fn read<R: ::std::io::Read>(reader: &mut R, logger: Arc<Logger>) -> Result<Self, DecodeError> {
 229                 let destination_script = Readable::read(reader)?;
 230                 let funding_redeemscript = Readable::read(reader)?;
 231                 let local_commitment = Readable::read(reader)?;
 232                 let prev_local_commitment = Readable::read(reader)?;
 233
 234                 let key_storage = Readable::read(reader)?;
 235
 236                 let pending_claim_requests_len: u64 = Readable::read(reader)?;
 237                 let mut pending_claim_requests = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
 238                 for _ in 0..pending_claim_requests_len {
 239                         pending_claim_requests.insert(Readable::read(reader)?, Readable::read(reader)?);
 240                 }
 241
 242                 let claimable_outpoints_len: u64 = Readable::read(reader)?;
 243                 let mut claimable_outpoints = HashMap::with_capacity(cmp::min(pending_claim_requests_len as usize, MAX_ALLOC_SIZE / 128));
 244                 for _ in 0..claimable_outpoints_len {
 245                         let outpoint = Readable::read(reader)?;
 246                         let ancestor_claim_txid = Readable::read(reader)?;
 247                         let height = Readable::read(reader)?;
 248                         claimable_outpoints.insert(outpoint, (ancestor_claim_txid, height));
 249                 }
 250                 let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
 251                 let mut onchain_events_waiting_threshold_conf = HashMap::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
 252                 for _ in 0..waiting_threshold_conf_len {
 253                         let height_target = Readable::read(reader)?;
 254                         let events_len: u64 = Readable::read(reader)?;
 255                         let mut events = Vec::with_capacity(cmp::min(events_len as usize, MAX_ALLOC_SIZE / 128));
 256                         for _ in 0..events_len {
 257                                 let ev = match <u8 as Readable>::read(reader)? {
 258                                         0 => {
 259                                                 let claim_request = Readable::read(reader)?;
 260                                                 OnchainEvent::Claim {
 261                                                         claim_request
 262                                                 }
 263                                         },
 264                                         1 => {
 265                                                 let outpoint = Readable::read(reader)?;
 266                                                 let input_material = Readable::read(reader)?;
 267                                                 OnchainEvent::ContentiousOutpoint {
 268                                                         outpoint,
 269                                                         input_material
 270                                                 }
 271                                         }
 272                                         _ => return Err(DecodeError::InvalidValue),
 273                                 };
 274                                 events.push(ev);
 275                         }
 276                         onchain_events_waiting_threshold_conf.insert(height_target, events);
 277                 }
 278
 279                 Ok(OnchainTxHandler {
 280                         destination_script,
 281                         funding_redeemscript,
 282                         local_commitment,
 283                         prev_local_commitment,
 284                         key_storage,
 285                         claimable_outpoints,
 286                         pending_claim_requests,
 287                         onchain_events_waiting_threshold_conf,
 288                         secp_ctx: Secp256k1::new(),
 289                         logger,
 290                 })
 291         }
 292 }
 293
 294 impl<ChanSigner: ChannelKeys> OnchainTxHandler<ChanSigner> {
 295         pub(super) fn new(destination_script: Script, keys: ChanSigner, funding_redeemscript: Script, logger: Arc<Logger>) -> Self {
 296
 297                 let key_storage = keys;
 298
 299                 OnchainTxHandler {
 300                         destination_script,
 301                         funding_redeemscript,
 302                         local_commitment: None,
 303                         prev_local_commitment: None,
 304                         key_storage,
 305                         pending_claim_requests: HashMap::new(),
 306                         claimable_outpoints: HashMap::new(),
 307                         onchain_events_waiting_threshold_conf: HashMap::new(),
 308
 309                         secp_ctx: Secp256k1::new(),
 310                         logger,
 311                 }
 312         }
 313
 314         pub(super) fn get_witnesses_weight(inputs: &[InputDescriptors]) -> usize {
 315                 let mut tx_weight = 2; // count segwit flags
 316                 for inp in inputs {
 317                         // We use expected weight (and not actual) as signatures and time lock delays may vary
 318                         tx_weight +=  match inp {
 319                                 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
 320                                 &InputDescriptors::RevokedOfferedHTLC => {
 321                                         1 + 1 + 73 + 1 + 33 + 1 + 133
 322                                 },
 323                                 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
 324                                 &InputDescriptors::RevokedReceivedHTLC => {
 325                                         1 + 1 + 73 + 1 + 33 + 1 + 139
 326                                 },
 327                                 // number_of_witness_elements + sig_length + remotehtlc_sig  + preimage_length + preimage + witness_script_length + witness_script
 328                                 &InputDescriptors::OfferedHTLC => {
 329                                         1 + 1 + 73 + 1 + 32 + 1 + 133
 330                                 },
 331                                 // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
 332                                 &InputDescriptors::ReceivedHTLC => {
 333                                         1 + 1 + 73 + 1 + 1 + 1 + 139
 334                                 },
 335                                 // number_of_witness_elements + sig_length + revocation_sig + true_length + op_true + witness_script_length + witness_script
 336                                 &InputDescriptors::RevokedOutput => {
 337                                         1 + 1 + 73 + 1 + 1 + 1 + 77
 338                                 },
 339                         };
 340                 }
 341                 tx_weight
 342         }
 343
 344         /// In LN, output claimed are time-sensitive, which means we have to spend them before reaching some timelock expiration. At in-channel
 345         /// 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
 346         /// height than once reached we should generate a new bumped "version" of the claim tx to be sure than we safely claim outputs before
 347         /// than our counterparty can do it too. If timelock expires soon, height timer is going to be scale down in consequence to increase
 348         /// frequency of the bump and so increase our bets of success.
 349         fn get_height_timer(current_height: u32, timelock_expiration: u32) -> u32 {
 350                 if timelock_expiration <= current_height + 3 {
 351                         return current_height + 1
 352                 } else if timelock_expiration - current_height <= 15 {
 353                         return current_height + 3
 354                 }
 355                 current_height + 15
 356         }
 357
 358         /// 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
 359         /// (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.
 360         fn generate_claim_tx<F: Deref>(&self, height: u32, cached_claim_datas: &ClaimTxBumpMaterial, fee_estimator: F) -> Option<(u32, u64, Transaction)>
 361                 where F::Target: FeeEstimator
 362         {
 363                 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
 364                 let mut inputs = Vec::new();
 365                 for outp in cached_claim_datas.per_input_material.keys() {
 366                         log_trace!(self, "Outpoint {}:{}", outp.txid, outp.vout);
 367                         inputs.push(TxIn {
 368                                 previous_output: *outp,
 369                                 script_sig: Script::new(),
 370                                 sequence: 0xfffffffd,
 371                                 witness: Vec::new(),
 372                         });
 373                 }
 374                 let mut bumped_tx = Transaction {
 375                         version: 2,
 376                         lock_time: 0,
 377                         input: inputs,
 378                         output: vec![TxOut {
 379                                 script_pubkey: self.destination_script.clone(),
 380                                 value: 0
 381                         }],
 382                 };
 383
 384                 macro_rules! RBF_bump {
 385                         ($amount: expr, $old_feerate: expr, $fee_estimator: expr, $predicted_weight: expr) => {
 386                                 {
 387                                         let mut used_feerate;
 388                                         // If old feerate inferior to actual one given back by Fee Estimator, use it to compute new fee...
 389                                         let new_fee = if $old_feerate < $fee_estimator.get_est_sat_per_1000_weight(ConfirmationTarget::HighPriority) {
 390                                                 let mut value = $amount;
 391                                                 if subtract_high_prio_fee!(self, $fee_estimator, value, $predicted_weight, used_feerate) {
 392                                                         // Overflow check is done in subtract_high_prio_fee
 393                                                         $amount - value
 394                                                 } else {
 395                                                         log_trace!(self, "Can't new-estimation bump new claiming tx, amount {} is too small", $amount);
 396                                                         return None;
 397                                                 }
 398                                         // ...else just increase the previous feerate by 25% (because that's a nice number)
 399                                         } else {
 400                                                 let fee = $old_feerate * $predicted_weight / 750;
 401                                                 if $amount <= fee {
 402                                                         log_trace!(self, "Can't 25% bump new claiming tx, amount {} is too small", $amount);
 403                                                         return None;
 404                                                 }
 405                                                 fee
 406                                         };
 407
 408                                         let previous_fee = $old_feerate * $predicted_weight / 1000;
 409                                         let min_relay_fee = MIN_RELAY_FEE_SAT_PER_1000_WEIGHT * $predicted_weight / 1000;
 410                                         // BIP 125 Opt-in Full Replace-by-Fee Signaling
 411                                         //      * 3. The replacement transaction pays an absolute fee of at least the sum paid by the original transactions.
 412                                         //      * 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.
 413                                         let new_fee = if new_fee < previous_fee + min_relay_fee {
 414                                                 new_fee + previous_fee + min_relay_fee - new_fee
 415                                         } else {
 416                                                 new_fee
 417                                         };
 418                                         Some((new_fee, new_fee * 1000 / $predicted_weight))
 419                                 }
 420                         }
 421                 }
 422
 423                 // Compute new height timer to decide when we need to regenerate a new bumped version of the claim tx (if we
 424                 // didn't receive confirmation of it before, or not enough reorg-safe depth on top of it).
 425                 let new_timer = Self::get_height_timer(height, cached_claim_datas.soonest_timelock);
 426                 let mut inputs_witnesses_weight = 0;
 427                 let mut amt = 0;
 428                 for per_outp_material in cached_claim_datas.per_input_material.values() {
 429                         match per_outp_material {
 430                                 &InputMaterial::Revoked { ref witness_script, ref is_htlc, ref amount, .. } => {
 431                                         inputs_witnesses_weight += Self::get_witnesses_weight(if !is_htlc { &[InputDescriptors::RevokedOutput] } else if HTLCType::scriptlen_to_htlctype(witness_script.len()) == Some(HTLCType::OfferedHTLC) { &[InputDescriptors::RevokedOfferedHTLC] } else if HTLCType::scriptlen_to_htlctype(witness_script.len()) == Some(HTLCType::AcceptedHTLC) { &[InputDescriptors::RevokedReceivedHTLC] } else { unreachable!() });
 432                                         amt += *amount;
 433                                 },
 434                                 &InputMaterial::RemoteHTLC { ref preimage, ref amount, .. } => {
 435                                         inputs_witnesses_weight += Self::get_witnesses_weight(if preimage.is_some() { &[InputDescriptors::OfferedHTLC] } else { &[InputDescriptors::ReceivedHTLC] });
 436                                         amt += *amount;
 437                                 },
 438                                 &InputMaterial::LocalHTLC { .. } => { return None; }
 439                         }
 440                 }
 441
 442                 let predicted_weight = bumped_tx.get_weight() + inputs_witnesses_weight;
 443                 let mut new_feerate;
 444                 // If old feerate is 0, first iteration of this claim, use normal fee calculation
 445                 if cached_claim_datas.feerate_previous != 0 {
 446                         if let Some((new_fee, feerate)) = RBF_bump!(amt, cached_claim_datas.feerate_previous, fee_estimator, predicted_weight as u64) {
 447                                 // If new computed fee is superior at the whole claimable amount burn all in fees
 448                                 if new_fee > amt {
 449                                         bumped_tx.output[0].value = 0;
 450                                 } else {
 451                                         bumped_tx.output[0].value = amt - new_fee;
 452                                 }
 453                                 new_feerate = feerate;
 454                         } else { return None; }
 455                 } else {
 456                         if subtract_high_prio_fee!(self, fee_estimator, amt, predicted_weight, new_feerate) {
 457                                 bumped_tx.output[0].value = amt;
 458                         } else { return None; }
 459                 }
 460                 assert!(new_feerate != 0);
 461
 462                 for (i, (outp, per_outp_material)) in cached_claim_datas.per_input_material.iter().enumerate() {
 463                         match per_outp_material {
 464                                 &InputMaterial::Revoked { ref witness_script, ref pubkey, ref key, ref is_htlc, ref amount } => {
 465                                         let sighash_parts = bip143::SighashComponents::new(&bumped_tx);
 466                                         let sighash = hash_to_message!(&sighash_parts.sighash_all(&bumped_tx.input[i], &witness_script, *amount)[..]);
 467                                         let sig = self.secp_ctx.sign(&sighash, &key);
 468                                         bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
 469                                         bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
 470                                         if *is_htlc {
 471                                                 bumped_tx.input[i].witness.push(pubkey.unwrap().clone().serialize().to_vec());
 472                                         } else {
 473                                                 bumped_tx.input[i].witness.push(vec!(1));
 474                                         }
 475                                         bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
 476                                         log_trace!(self, "Going to broadcast Penalty Transaction {} claiming revoked {} output {} from {} with new feerate {}...", bumped_tx.txid(), if !is_htlc { "to_local" } else if HTLCType::scriptlen_to_htlctype(witness_script.len()) == Some(HTLCType::OfferedHTLC) { "offered" } else if HTLCType::scriptlen_to_htlctype(witness_script.len()) == Some(HTLCType::AcceptedHTLC) { "received" } else { "" }, outp.vout, outp.txid, new_feerate);
 477                                 },
 478                                 &InputMaterial::RemoteHTLC { ref witness_script, ref key, ref preimage, ref amount, ref locktime } => {
 479                                         if !preimage.is_some() { bumped_tx.lock_time = *locktime }; // Right now we don't aggregate time-locked transaction, if we do we should set lock_time before to avoid breaking hash computation
 480                                         let sighash_parts = bip143::SighashComponents::new(&bumped_tx);
 481                                         let sighash = hash_to_message!(&sighash_parts.sighash_all(&bumped_tx.input[i], &witness_script, *amount)[..]);
 482                                         let sig = self.secp_ctx.sign(&sighash, &key);
 483                                         bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
 484                                         bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
 485                                         if let &Some(preimage) = preimage {
 486                                                 bumped_tx.input[i].witness.push(preimage.clone().0.to_vec());
 487                                         } else {
 488                                                 bumped_tx.input[i].witness.push(vec![]);
 489                                         }
 490                                         bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
 491                                         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);
 492                                 },
 493                                 &InputMaterial::LocalHTLC { .. } => {
 494                                         //TODO : Given that Local Commitment Transaction and HTLC-Timeout/HTLC-Success are counter-signed by peer, we can't
 495                                         // RBF them. Need a Lightning specs change and package relay modification :
 496                                         // https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2018-November/016518.html
 497                                         return None;
 498                                 }
 499                         }
 500                 }
 501                 log_trace!(self, "...with timer {}", new_timer);
 502                 assert!(predicted_weight >= bumped_tx.get_weight());
 503                 Some((new_timer, new_feerate, bumped_tx))
 504         }
 505
 506         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)
 507                 where B::Target: BroadcasterInterface,
 508                       F::Target: FeeEstimator
 509         {
 510                 log_trace!(self, "Block at height {} connected with {} claim requests", height, claimable_outpoints.len());
 511                 let mut new_claims = Vec::new();
 512                 let mut aggregated_claim = HashMap::new();
 513                 let mut aggregated_soonest = ::std::u32::MAX;
 514
 515                 // Try to aggregate outputs if their timelock expiration isn't imminent (absolute_timelock
 516                 // <= CLTV_SHARED_CLAIM_BUFFER) and they don't require an immediate nLockTime (aggregable).
 517                 for req in claimable_outpoints {
 518                         // Don't claim a outpoint twice that would be bad for privacy and may uselessly lock a CPFP input for a while
 519                         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 {
 520                                 log_trace!(self, "Test if outpoint can be aggregated with expiration {} against {}", req.absolute_timelock, height + CLTV_SHARED_CLAIM_BUFFER);
 521                                 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
 522                                         let mut single_input = HashMap::new();
 523                                         single_input.insert(req.outpoint, req.witness_data);
 524                                         new_claims.push((req.absolute_timelock, single_input));
 525                                 } else {
 526                                         aggregated_claim.insert(req.outpoint, req.witness_data);
 527                                         if req.absolute_timelock < aggregated_soonest {
 528                                                 aggregated_soonest = req.absolute_timelock;
 529                                         }
 530                                 }
 531                         }
 532                 }
 533                 new_claims.push((aggregated_soonest, aggregated_claim));
 534
 535                 // Generate claim transactions and track them to bump if necessary at
 536                 // height timer expiration (i.e in how many blocks we're going to take action).
 537                 for claim in new_claims {
 538                         let mut claim_material = ClaimTxBumpMaterial { height_timer: 0, feerate_previous: 0, soonest_timelock: claim.0, per_input_material: claim.1.clone() };
 539                         if let Some((new_timer, new_feerate, tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator) {
 540                                 claim_material.height_timer = new_timer;
 541                                 claim_material.feerate_previous = new_feerate;
 542                                 let txid = tx.txid();
 543                                 self.pending_claim_requests.insert(txid, claim_material);
 544                                 for k in claim.1.keys() {
 545                                         log_trace!(self, "Registering claiming request for {}:{}", k.txid, k.vout);
 546                                         self.claimable_outpoints.insert(k.clone(), (txid, height));
 547                                 }
 548                                 log_trace!(self, "Broadcast onchain {}", log_tx!(tx));
 549                                 broadcaster.broadcast_transaction(&tx);
 550                         }
 551                 }
 552
 553                 let mut bump_candidates = HashSet::new();
 554                 for tx in txn_matched {
 555                         // Scan all input to verify is one of the outpoint spent is of interest for us
 556                         let mut claimed_outputs_material = Vec::new();
 557                         for inp in &tx.input {
 558                                 if let Some(first_claim_txid_height) = self.claimable_outpoints.get(&inp.previous_output) {
 559                                         // If outpoint has claim request pending on it...
 560                                         if let Some(claim_material) = self.pending_claim_requests.get_mut(&first_claim_txid_height.0) {
 561                                                 //... we need to verify equality between transaction outpoints and claim request
 562                                                 // outpoints to know if transaction is the original claim or a bumped one issued
 563                                                 // by us.
 564                                                 let mut set_equality = true;
 565                                                 if claim_material.per_input_material.len() != tx.input.len() {
 566                                                         set_equality = false;
 567                                                 } else {
 568                                                         for (claim_inp, tx_inp) in claim_material.per_input_material.keys().zip(tx.input.iter()) {
 569                                                                 if *claim_inp != tx_inp.previous_output {
 570                                                                         set_equality = false;
 571                                                                 }
 572                                                         }
 573                                                 }
 574
 575                                                 macro_rules! clean_claim_request_after_safety_delay {
 576                                                         () => {
 577                                                                 let new_event = OnchainEvent::Claim { claim_request: first_claim_txid_height.0.clone() };
 578                                                                 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
 579                                                                         hash_map::Entry::Occupied(mut entry) => {
 580                                                                                 if !entry.get().contains(&new_event) {
 581                                                                                         entry.get_mut().push(new_event);
 582                                                                                 }
 583                                                                         },
 584                                                                         hash_map::Entry::Vacant(entry) => {
 585                                                                                 entry.insert(vec![new_event]);
 586                                                                         }
 587                                                                 }
 588                                                         }
 589                                                 }
 590
 591                                                 // If this is our transaction (or our counterparty spent all the outputs
 592                                                 // before we could anyway with same inputs order than us), wait for
 593                                                 // ANTI_REORG_DELAY and clean the RBF tracking map.
 594                                                 if set_equality {
 595                                                         clean_claim_request_after_safety_delay!();
 596                                                 } else { // If false, generate new claim request with update outpoint set
 597                                                         let mut at_least_one_drop = false;
 598                                                         for input in tx.input.iter() {
 599                                                                 if let Some(input_material) = claim_material.per_input_material.remove(&input.previous_output) {
 600                                                                         claimed_outputs_material.push((input.previous_output, input_material));
 601                                                                         at_least_one_drop = true;
 602                                                                 }
 603                                                                 // If there are no outpoints left to claim in this request, drop it entirely after ANTI_REORG_DELAY.
 604                                                                 if claim_material.per_input_material.is_empty() {
 605                                                                         clean_claim_request_after_safety_delay!();
 606                                                                 }
 607                                                         }
 608                                                         //TODO: recompute soonest_timelock to avoid wasting a bit on fees
 609                                                         if at_least_one_drop {
 610                                                                 bump_candidates.insert(first_claim_txid_height.0.clone());
 611                                                         }
 612                                                 }
 613                                                 break; //No need to iterate further, either tx is our or their
 614                                         } else {
 615                                                 panic!("Inconsistencies between pending_claim_requests map and claimable_outpoints map");
 616                                         }
 617                                 }
 618                         }
 619                         for (outpoint, input_material) in claimed_outputs_material.drain(..) {
 620                                 let new_event = OnchainEvent::ContentiousOutpoint { outpoint, input_material };
 621                                 match self.onchain_events_waiting_threshold_conf.entry(height + ANTI_REORG_DELAY - 1) {
 622                                         hash_map::Entry::Occupied(mut entry) => {
 623                                                 if !entry.get().contains(&new_event) {
 624                                                         entry.get_mut().push(new_event);
 625                                                 }
 626                                         },
 627                                         hash_map::Entry::Vacant(entry) => {
 628                                                 entry.insert(vec![new_event]);
 629                                         }
 630                                 }
 631                         }
 632                 }
 633
 634                 // After security delay, either our claim tx got enough confs or outpoint is definetely out of reach
 635                 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&height) {
 636                         for ev in events {
 637                                 match ev {
 638                                         OnchainEvent::Claim { claim_request } => {
 639                                                 // We may remove a whole set of claim outpoints here, as these one may have
 640                                                 // been aggregated in a single tx and claimed so atomically
 641                                                 if let Some(bump_material) = self.pending_claim_requests.remove(&claim_request) {
 642                                                         for outpoint in bump_material.per_input_material.keys() {
 643                                                                 self.claimable_outpoints.remove(&outpoint);
 644                                                         }
 645                                                 }
 646                                         },
 647                                         OnchainEvent::ContentiousOutpoint { outpoint, .. } => {
 648                                                 self.claimable_outpoints.remove(&outpoint);
 649                                         }
 650                                 }
 651                         }
 652                 }
 653
 654                 // Check if any pending claim request must be rescheduled
 655                 for (first_claim_txid, ref claim_data) in self.pending_claim_requests.iter() {
 656                         if claim_data.height_timer == height {
 657                                 bump_candidates.insert(*first_claim_txid);
 658                         }
 659                 }
 660
 661                 // Build, bump and rebroadcast tx accordingly
 662                 log_trace!(self, "Bumping {} candidates", bump_candidates.len());
 663                 for first_claim_txid in bump_candidates.iter() {
 664                         if let Some((new_timer, new_feerate)) = {
 665                                 if let Some(claim_material) = self.pending_claim_requests.get(first_claim_txid) {
 666                                         if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator) {
 667                                                 log_trace!(self, "Broadcast onchain {}", log_tx!(bump_tx));
 668                                                 broadcaster.broadcast_transaction(&bump_tx);
 669                                                 Some((new_timer, new_feerate))
 670                                         } else { None }
 671                                 } else { unreachable!(); }
 672                         } {
 673                                 if let Some(claim_material) = self.pending_claim_requests.get_mut(first_claim_txid) {
 674                                         claim_material.height_timer = new_timer;
 675                                         claim_material.feerate_previous = new_feerate;
 676                                 } else { unreachable!(); }
 677                         }
 678                 }
 679         }
 680
 681         pub(super) fn block_disconnected<B: Deref, F: Deref>(&mut self, height: u32, broadcaster: B, fee_estimator: F)
 682                 where B::Target: BroadcasterInterface,
 683                       F::Target: FeeEstimator
 684         {
 685                 let mut bump_candidates = HashMap::new();
 686                 if let Some(events) = self.onchain_events_waiting_threshold_conf.remove(&(height + ANTI_REORG_DELAY - 1)) {
 687                         //- our claim tx on a commitment tx output
 688                         //- resurect outpoint back in its claimable set and regenerate tx
 689                         for ev in events {
 690                                 match ev {
 691                                         OnchainEvent::ContentiousOutpoint { outpoint, input_material } => {
 692                                                 if let Some(ancestor_claimable_txid) = self.claimable_outpoints.get(&outpoint) {
 693                                                         if let Some(claim_material) = self.pending_claim_requests.get_mut(&ancestor_claimable_txid.0) {
 694                                                                 claim_material.per_input_material.insert(outpoint, input_material);
 695                                                                 // Using a HashMap guarantee us than if we have multiple outpoints getting
 696                                                                 // resurrected only one bump claim tx is going to be broadcast
 697                                                                 bump_candidates.insert(ancestor_claimable_txid.clone(), claim_material.clone());
 698                                                         }
 699                                                 }
 700                                         },
 701                                         _ => {},
 702                                 }
 703                         }
 704                 }
 705                 for (_, claim_material) in bump_candidates.iter_mut() {
 706                         if let Some((new_timer, new_feerate, bump_tx)) = self.generate_claim_tx(height, &claim_material, &*fee_estimator) {
 707                                 claim_material.height_timer = new_timer;
 708                                 claim_material.feerate_previous = new_feerate;
 709                                 broadcaster.broadcast_transaction(&bump_tx);
 710                         }
 711                 }
 712                 for (ancestor_claim_txid, claim_material) in bump_candidates.drain() {
 713                         self.pending_claim_requests.insert(ancestor_claim_txid.0, claim_material);
 714                 }
 715                 //TODO: if we implement cross-block aggregated claim transaction we need to refresh set of outpoints and regenerate tx but
 716                 // right now if one of the outpoint get disconnected, just erase whole pending claim request.
 717                 let mut remove_request = Vec::new();
 718                 self.claimable_outpoints.retain(|_, ref v|
 719                         if v.1 == height {
 720                         remove_request.push(v.0.clone());
 721                         false
 722                         } else { true });
 723                 for req in remove_request {
 724                         self.pending_claim_requests.remove(&req);
 725                 }
 726         }
 727
 728         pub(super) fn provide_latest_local_tx(&mut self, tx: LocalCommitmentTransaction) {
 729                 self.prev_local_commitment = self.local_commitment.take();
 730                 self.local_commitment = Some(tx);
 731         }
 732 }