_ Git - rust-lightning/blob - lightning/src/chain/package.rs

   1 // This file is Copyright its original authors, visible in version control
   2 // history.
   3 //
   4 // This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
   5 // or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   6 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
   7 // You may not use this file except in accordance with one or both of these
   8 // licenses.
   9
  10 //! Various utilities to assemble claimable outpoints in package of one or more transactions. Those
  11 //! packages are attached metadata, guiding their aggregable or fee-bumping re-schedule. This file
  12 //! also includes witness weight computation and fee computation methods.
  13
  14 use bitcoin::blockdata::constants::WITNESS_SCALE_FACTOR;
  15 use bitcoin::blockdata::transaction::{TxOut,TxIn, Transaction, EcdsaSighashType};
  16 use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
  17 use bitcoin::blockdata::script::Script;
  18
  19 use bitcoin::hash_types::Txid;
  20
  21 use bitcoin::secp256k1::{SecretKey,PublicKey};
  22
  23 use crate::ln::PaymentPreimage;
  24 use crate::ln::chan_utils::{TxCreationKeys, HTLCOutputInCommitment};
  25 use crate::ln::chan_utils;
  26 use crate::ln::msgs::DecodeError;
  27 use crate::chain::chaininterface::{FeeEstimator, ConfirmationTarget, MIN_RELAY_FEE_SAT_PER_1000_WEIGHT};
  28 use crate::chain::keysinterface::Sign;
  29 #[cfg(anchors)]
  30 use crate::chain::onchaintx::ExternalHTLCClaim;
  31 use crate::chain::onchaintx::OnchainTxHandler;
  32 use crate::util::logger::Logger;
  33 use crate::util::ser::{Readable, Writer, Writeable};
  34
  35 use crate::io;
  36 use crate::prelude::*;
  37 use core::cmp;
  38 #[cfg(anchors)]
  39 use core::convert::TryInto;
  40 use core::mem;
  41 use core::ops::Deref;
  42 use bitcoin::{PackedLockTime, Sequence, Witness};
  43
  44 use super::chaininterface::LowerBoundedFeeEstimator;
  45
  46 const MAX_ALLOC_SIZE: usize = 64*1024;
  47
  48
  49 pub(crate) fn weight_revoked_offered_htlc(opt_anchors: bool) -> u64 {
  50         // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
  51         const WEIGHT_REVOKED_OFFERED_HTLC: u64 = 1 + 1 + 73 + 1 + 33 + 1 + 133;
  52         const WEIGHT_REVOKED_OFFERED_HTLC_ANCHORS: u64 = WEIGHT_REVOKED_OFFERED_HTLC + 3; // + OP_1 + OP_CSV + OP_DROP
  53         if opt_anchors { WEIGHT_REVOKED_OFFERED_HTLC_ANCHORS } else { WEIGHT_REVOKED_OFFERED_HTLC }
  54 }
  55
  56 pub(crate) fn weight_revoked_received_htlc(opt_anchors: bool) -> u64 {
  57         // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
  58         const WEIGHT_REVOKED_RECEIVED_HTLC: u64 = 1 + 1 + 73 + 1 + 33 + 1 +  139;
  59         const WEIGHT_REVOKED_RECEIVED_HTLC_ANCHORS: u64 = WEIGHT_REVOKED_RECEIVED_HTLC + 3; // + OP_1 + OP_CSV + OP_DROP
  60         if opt_anchors { WEIGHT_REVOKED_RECEIVED_HTLC_ANCHORS } else { WEIGHT_REVOKED_RECEIVED_HTLC }
  61 }
  62
  63 pub(crate) fn weight_offered_htlc(opt_anchors: bool) -> u64 {
  64         // number_of_witness_elements + sig_length + counterpartyhtlc_sig  + preimage_length + preimage + witness_script_length + witness_script
  65         const WEIGHT_OFFERED_HTLC: u64 = 1 + 1 + 73 + 1 + 32 + 1 + 133;
  66         const WEIGHT_OFFERED_HTLC_ANCHORS: u64 = WEIGHT_OFFERED_HTLC + 3; // + OP_1 + OP_CSV + OP_DROP
  67         if opt_anchors { WEIGHT_OFFERED_HTLC_ANCHORS } else { WEIGHT_OFFERED_HTLC }
  68 }
  69
  70 pub(crate) fn weight_received_htlc(opt_anchors: bool) -> u64 {
  71         // number_of_witness_elements + sig_length + counterpartyhtlc_sig + empty_vec_length + empty_vec + witness_script_length + witness_script
  72         const WEIGHT_RECEIVED_HTLC: u64 = 1 + 1 + 73 + 1 + 1 + 1 + 139;
  73         const WEIGHT_RECEIVED_HTLC_ANCHORS: u64 = WEIGHT_RECEIVED_HTLC + 3; // + OP_1 + OP_CSV + OP_DROP
  74         if opt_anchors { WEIGHT_RECEIVED_HTLC_ANCHORS } else { WEIGHT_RECEIVED_HTLC }
  75 }
  76
  77 // number_of_witness_elements + sig_length + revocation_sig + true_length + op_true + witness_script_length + witness_script
  78 pub(crate) const WEIGHT_REVOKED_OUTPUT: u64 = 1 + 1 + 73 + 1 + 1 + 1 + 77;
  79
  80 /// Height delay at which transactions are fee-bumped/rebroadcasted with a low priority.
  81 const LOW_FREQUENCY_BUMP_INTERVAL: u32 = 15;
  82 /// Height delay at which transactions are fee-bumped/rebroadcasted with a middle priority.
  83 const MIDDLE_FREQUENCY_BUMP_INTERVAL: u32 = 3;
  84 /// Height delay at which transactions are fee-bumped/rebroadcasted with a high priority.
  85 const HIGH_FREQUENCY_BUMP_INTERVAL: u32 = 1;
  86
  87 /// A struct to describe a revoked output and corresponding information to generate a solving
  88 /// witness spending a commitment `to_local` output or a second-stage HTLC transaction output.
  89 ///
  90 /// CSV and pubkeys are used as part of a witnessScript redeeming a balance output, amount is used
  91 /// as part of the signature hash and revocation secret to generate a satisfying witness.
  92 #[derive(Clone, PartialEq, Eq)]
  93 pub(crate) struct RevokedOutput {
  94         per_commitment_point: PublicKey,
  95         counterparty_delayed_payment_base_key: PublicKey,
  96         counterparty_htlc_base_key: PublicKey,
  97         per_commitment_key: SecretKey,
  98         weight: u64,
  99         amount: u64,
 100         on_counterparty_tx_csv: u16,
 101 }
 102
 103 impl RevokedOutput {
 104         pub(crate) fn build(per_commitment_point: PublicKey, counterparty_delayed_payment_base_key: PublicKey, counterparty_htlc_base_key: PublicKey, per_commitment_key: SecretKey, amount: u64, on_counterparty_tx_csv: u16) -> Self {
 105                 RevokedOutput {
 106                         per_commitment_point,
 107                         counterparty_delayed_payment_base_key,
 108                         counterparty_htlc_base_key,
 109                         per_commitment_key,
 110                         weight: WEIGHT_REVOKED_OUTPUT,
 111                         amount,
 112                         on_counterparty_tx_csv
 113                 }
 114         }
 115 }
 116
 117 impl_writeable_tlv_based!(RevokedOutput, {
 118         (0, per_commitment_point, required),
 119         (2, counterparty_delayed_payment_base_key, required),
 120         (4, counterparty_htlc_base_key, required),
 121         (6, per_commitment_key, required),
 122         (8, weight, required),
 123         (10, amount, required),
 124         (12, on_counterparty_tx_csv, required),
 125 });
 126
 127 /// A struct to describe a revoked offered output and corresponding information to generate a
 128 /// solving witness.
 129 ///
 130 /// HTLCOuputInCommitment (hash timelock, direction) and pubkeys are used to generate a suitable
 131 /// witnessScript.
 132 ///
 133 /// CSV is used as part of a witnessScript redeeming a balance output, amount is used as part
 134 /// of the signature hash and revocation secret to generate a satisfying witness.
 135 #[derive(Clone, PartialEq, Eq)]
 136 pub(crate) struct RevokedHTLCOutput {
 137         per_commitment_point: PublicKey,
 138         counterparty_delayed_payment_base_key: PublicKey,
 139         counterparty_htlc_base_key: PublicKey,
 140         per_commitment_key: SecretKey,
 141         weight: u64,
 142         amount: u64,
 143         htlc: HTLCOutputInCommitment,
 144 }
 145
 146 impl RevokedHTLCOutput {
 147         pub(crate) fn build(per_commitment_point: PublicKey, counterparty_delayed_payment_base_key: PublicKey, counterparty_htlc_base_key: PublicKey, per_commitment_key: SecretKey, amount: u64, htlc: HTLCOutputInCommitment, opt_anchors: bool) -> Self {
 148                 let weight = if htlc.offered { weight_revoked_offered_htlc(opt_anchors) } else { weight_revoked_received_htlc(opt_anchors) };
 149                 RevokedHTLCOutput {
 150                         per_commitment_point,
 151                         counterparty_delayed_payment_base_key,
 152                         counterparty_htlc_base_key,
 153                         per_commitment_key,
 154                         weight,
 155                         amount,
 156                         htlc
 157                 }
 158         }
 159 }
 160
 161 impl_writeable_tlv_based!(RevokedHTLCOutput, {
 162         (0, per_commitment_point, required),
 163         (2, counterparty_delayed_payment_base_key, required),
 164         (4, counterparty_htlc_base_key, required),
 165         (6, per_commitment_key, required),
 166         (8, weight, required),
 167         (10, amount, required),
 168         (12, htlc, required),
 169 });
 170
 171 /// A struct to describe a HTLC output on a counterparty commitment transaction.
 172 ///
 173 /// HTLCOutputInCommitment (hash, timelock, directon) and pubkeys are used to generate a suitable
 174 /// witnessScript.
 175 ///
 176 /// The preimage is used as part of the witness.
 177 #[derive(Clone, PartialEq, Eq)]
 178 pub(crate) struct CounterpartyOfferedHTLCOutput {
 179         per_commitment_point: PublicKey,
 180         counterparty_delayed_payment_base_key: PublicKey,
 181         counterparty_htlc_base_key: PublicKey,
 182         preimage: PaymentPreimage,
 183         htlc: HTLCOutputInCommitment,
 184         opt_anchors: Option<()>,
 185 }
 186
 187 impl CounterpartyOfferedHTLCOutput {
 188         pub(crate) fn build(per_commitment_point: PublicKey, counterparty_delayed_payment_base_key: PublicKey, counterparty_htlc_base_key: PublicKey, preimage: PaymentPreimage, htlc: HTLCOutputInCommitment, opt_anchors: bool) -> Self {
 189                 CounterpartyOfferedHTLCOutput {
 190                         per_commitment_point,
 191                         counterparty_delayed_payment_base_key,
 192                         counterparty_htlc_base_key,
 193                         preimage,
 194                         htlc,
 195                         opt_anchors: if opt_anchors { Some(()) } else { None },
 196                 }
 197         }
 198
 199         fn opt_anchors(&self) -> bool {
 200                 self.opt_anchors.is_some()
 201         }
 202 }
 203
 204 impl_writeable_tlv_based!(CounterpartyOfferedHTLCOutput, {
 205         (0, per_commitment_point, required),
 206         (2, counterparty_delayed_payment_base_key, required),
 207         (4, counterparty_htlc_base_key, required),
 208         (6, preimage, required),
 209         (8, htlc, required),
 210         (10, opt_anchors, option),
 211 });
 212
 213 /// A struct to describe a HTLC output on a counterparty commitment transaction.
 214 ///
 215 /// HTLCOutputInCommitment (hash, timelock, directon) and pubkeys are used to generate a suitable
 216 /// witnessScript.
 217 #[derive(Clone, PartialEq, Eq)]
 218 pub(crate) struct CounterpartyReceivedHTLCOutput {
 219         per_commitment_point: PublicKey,
 220         counterparty_delayed_payment_base_key: PublicKey,
 221         counterparty_htlc_base_key: PublicKey,
 222         htlc: HTLCOutputInCommitment,
 223         opt_anchors: Option<()>,
 224 }
 225
 226 impl CounterpartyReceivedHTLCOutput {
 227         pub(crate) fn build(per_commitment_point: PublicKey, counterparty_delayed_payment_base_key: PublicKey, counterparty_htlc_base_key: PublicKey, htlc: HTLCOutputInCommitment, opt_anchors: bool) -> Self {
 228                 CounterpartyReceivedHTLCOutput {
 229                         per_commitment_point,
 230                         counterparty_delayed_payment_base_key,
 231                         counterparty_htlc_base_key,
 232                         htlc,
 233                         opt_anchors: if opt_anchors { Some(()) } else { None },
 234                 }
 235         }
 236
 237         fn opt_anchors(&self) -> bool {
 238                 self.opt_anchors.is_some()
 239         }
 240 }
 241
 242 impl_writeable_tlv_based!(CounterpartyReceivedHTLCOutput, {
 243         (0, per_commitment_point, required),
 244         (2, counterparty_delayed_payment_base_key, required),
 245         (4, counterparty_htlc_base_key, required),
 246         (6, htlc, required),
 247         (8, opt_anchors, option),
 248 });
 249
 250 /// A struct to describe a HTLC output on holder commitment transaction.
 251 ///
 252 /// Either offered or received, the amount is always used as part of the bip143 sighash.
 253 /// Preimage is only included as part of the witness in former case.
 254 #[derive(Clone, PartialEq, Eq)]
 255 pub(crate) struct HolderHTLCOutput {
 256         preimage: Option<PaymentPreimage>,
 257         amount_msat: u64,
 258         /// Defaults to 0 for HTLC-Success transactions, which have no expiry
 259         cltv_expiry: u32,
 260         opt_anchors: Option<()>,
 261 }
 262
 263 impl HolderHTLCOutput {
 264         pub(crate) fn build_offered(amount_msat: u64, cltv_expiry: u32, opt_anchors: bool) -> Self {
 265                 HolderHTLCOutput {
 266                         preimage: None,
 267                         amount_msat,
 268                         cltv_expiry,
 269                         opt_anchors: if opt_anchors { Some(()) } else { None } ,
 270                 }
 271         }
 272
 273         pub(crate) fn build_accepted(preimage: PaymentPreimage, amount_msat: u64, opt_anchors: bool) -> Self {
 274                 HolderHTLCOutput {
 275                         preimage: Some(preimage),
 276                         amount_msat,
 277                         cltv_expiry: 0,
 278                         opt_anchors: if opt_anchors { Some(()) } else { None } ,
 279                 }
 280         }
 281
 282         fn opt_anchors(&self) -> bool {
 283                 self.opt_anchors.is_some()
 284         }
 285 }
 286
 287 impl_writeable_tlv_based!(HolderHTLCOutput, {
 288         (0, amount_msat, required),
 289         (2, cltv_expiry, required),
 290         (4, preimage, option),
 291         (6, opt_anchors, option)
 292 });
 293
 294 /// A struct to describe the channel output on the funding transaction.
 295 ///
 296 /// witnessScript is used as part of the witness redeeming the funding utxo.
 297 #[derive(Clone, PartialEq, Eq)]
 298 pub(crate) struct HolderFundingOutput {
 299         funding_redeemscript: Script,
 300         funding_amount: Option<u64>,
 301         opt_anchors: Option<()>,
 302 }
 303
 304
 305 impl HolderFundingOutput {
 306         pub(crate) fn build(funding_redeemscript: Script, funding_amount: u64, opt_anchors: bool) -> Self {
 307                 HolderFundingOutput {
 308                         funding_redeemscript,
 309                         funding_amount: Some(funding_amount),
 310                         opt_anchors: if opt_anchors { Some(()) } else { None },
 311                 }
 312         }
 313
 314         fn opt_anchors(&self) -> bool {
 315                 self.opt_anchors.is_some()
 316         }
 317 }
 318
 319 impl_writeable_tlv_based!(HolderFundingOutput, {
 320         (0, funding_redeemscript, required),
 321         (2, opt_anchors, option),
 322         (3, funding_amount, option),
 323 });
 324
 325 /// A wrapper encapsulating all in-protocol differing outputs types.
 326 ///
 327 /// The generic API offers access to an outputs common attributes or allow transformation such as
 328 /// finalizing an input claiming the output.
 329 #[derive(Clone, PartialEq, Eq)]
 330 pub(crate) enum PackageSolvingData {
 331         RevokedOutput(RevokedOutput),
 332         RevokedHTLCOutput(RevokedHTLCOutput),
 333         CounterpartyOfferedHTLCOutput(CounterpartyOfferedHTLCOutput),
 334         CounterpartyReceivedHTLCOutput(CounterpartyReceivedHTLCOutput),
 335         HolderHTLCOutput(HolderHTLCOutput),
 336         HolderFundingOutput(HolderFundingOutput),
 337 }
 338
 339 impl PackageSolvingData {
 340         fn amount(&self) -> u64 {
 341                 let amt = match self {
 342                         PackageSolvingData::RevokedOutput(ref outp) => outp.amount,
 343                         PackageSolvingData::RevokedHTLCOutput(ref outp) => outp.amount,
 344                         PackageSolvingData::CounterpartyOfferedHTLCOutput(ref outp) => outp.htlc.amount_msat / 1000,
 345                         PackageSolvingData::CounterpartyReceivedHTLCOutput(ref outp) => outp.htlc.amount_msat / 1000,
 346                         PackageSolvingData::HolderHTLCOutput(ref outp) => {
 347                                 debug_assert!(outp.opt_anchors());
 348                                 outp.amount_msat / 1000
 349                         },
 350                         PackageSolvingData::HolderFundingOutput(ref outp) => {
 351                                 debug_assert!(outp.opt_anchors());
 352                                 outp.funding_amount.unwrap()
 353                         }
 354                 };
 355                 amt
 356         }
 357         fn weight(&self) -> usize {
 358                 match self {
 359                         PackageSolvingData::RevokedOutput(ref outp) => outp.weight as usize,
 360                         PackageSolvingData::RevokedHTLCOutput(ref outp) => outp.weight as usize,
 361                         PackageSolvingData::CounterpartyOfferedHTLCOutput(ref outp) => weight_offered_htlc(outp.opt_anchors()) as usize,
 362                         PackageSolvingData::CounterpartyReceivedHTLCOutput(ref outp) => weight_received_htlc(outp.opt_anchors()) as usize,
 363                         PackageSolvingData::HolderHTLCOutput(ref outp) => {
 364                                 debug_assert!(outp.opt_anchors());
 365                                 if outp.preimage.is_none() {
 366                                         weight_offered_htlc(true) as usize
 367                                 } else {
 368                                         weight_received_htlc(true) as usize
 369                                 }
 370                         },
 371                         // Since HolderFundingOutput maps to an untractable package that is already signed, its
 372                         // weight can be determined from the transaction itself.
 373                         PackageSolvingData::HolderFundingOutput(..) => unreachable!(),
 374                 }
 375         }
 376         fn is_compatible(&self, input: &PackageSolvingData) -> bool {
 377                 match self {
 378                         PackageSolvingData::RevokedOutput(..) => {
 379                                 match input {
 380                                         PackageSolvingData::RevokedHTLCOutput(..) => { true },
 381                                         PackageSolvingData::RevokedOutput(..) => { true },
 382                                         _ => { false }
 383                                 }
 384                         },
 385                         PackageSolvingData::RevokedHTLCOutput(..) => {
 386                                 match input {
 387                                         PackageSolvingData::RevokedOutput(..) => { true },
 388                                         PackageSolvingData::RevokedHTLCOutput(..) => { true },
 389                                         _ => { false }
 390                                 }
 391                         },
 392                         _ => { mem::discriminant(self) == mem::discriminant(&input) }
 393                 }
 394         }
 395         fn finalize_input<Signer: Sign>(&self, bumped_tx: &mut Transaction, i: usize, onchain_handler: &mut OnchainTxHandler<Signer>) -> bool {
 396                 match self {
 397                         PackageSolvingData::RevokedOutput(ref outp) => {
 398                                 let chan_keys = TxCreationKeys::derive_new(&onchain_handler.secp_ctx, &outp.per_commitment_point, &outp.counterparty_delayed_payment_base_key, &outp.counterparty_htlc_base_key, &onchain_handler.signer.pubkeys().revocation_basepoint, &onchain_handler.signer.pubkeys().htlc_basepoint);
 399                                 let witness_script = chan_utils::get_revokeable_redeemscript(&chan_keys.revocation_key, outp.on_counterparty_tx_csv, &chan_keys.broadcaster_delayed_payment_key);
 400                                 //TODO: should we panic on signer failure ?
 401                                 if let Ok(sig) = onchain_handler.signer.sign_justice_revoked_output(&bumped_tx, i, outp.amount, &outp.per_commitment_key, &onchain_handler.secp_ctx) {
 402                                         let mut ser_sig = sig.serialize_der().to_vec();
 403                                         ser_sig.push(EcdsaSighashType::All as u8);
 404                                         bumped_tx.input[i].witness.push(ser_sig);
 405                                         bumped_tx.input[i].witness.push(vec!(1));
 406                                         bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
 407                                 } else { return false; }
 408                         },
 409                         PackageSolvingData::RevokedHTLCOutput(ref outp) => {
 410                                 let chan_keys = TxCreationKeys::derive_new(&onchain_handler.secp_ctx, &outp.per_commitment_point, &outp.counterparty_delayed_payment_base_key, &outp.counterparty_htlc_base_key, &onchain_handler.signer.pubkeys().revocation_basepoint, &onchain_handler.signer.pubkeys().htlc_basepoint);
 411                                 let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&outp.htlc, onchain_handler.opt_anchors(), &chan_keys.broadcaster_htlc_key, &chan_keys.countersignatory_htlc_key, &chan_keys.revocation_key);
 412                                 //TODO: should we panic on signer failure ?
 413                                 if let Ok(sig) = onchain_handler.signer.sign_justice_revoked_htlc(&bumped_tx, i, outp.amount, &outp.per_commitment_key, &outp.htlc, &onchain_handler.secp_ctx) {
 414                                         let mut ser_sig = sig.serialize_der().to_vec();
 415                                         ser_sig.push(EcdsaSighashType::All as u8);
 416                                         bumped_tx.input[i].witness.push(ser_sig);
 417                                         bumped_tx.input[i].witness.push(chan_keys.revocation_key.clone().serialize().to_vec());
 418                                         bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
 419                                 } else { return false; }
 420                         },
 421                         PackageSolvingData::CounterpartyOfferedHTLCOutput(ref outp) => {
 422                                 let chan_keys = TxCreationKeys::derive_new(&onchain_handler.secp_ctx, &outp.per_commitment_point, &outp.counterparty_delayed_payment_base_key, &outp.counterparty_htlc_base_key, &onchain_handler.signer.pubkeys().revocation_basepoint, &onchain_handler.signer.pubkeys().htlc_basepoint);
 423                                 let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&outp.htlc, onchain_handler.opt_anchors(), &chan_keys.broadcaster_htlc_key, &chan_keys.countersignatory_htlc_key, &chan_keys.revocation_key);
 424
 425                                 if let Ok(sig) = onchain_handler.signer.sign_counterparty_htlc_transaction(&bumped_tx, i, &outp.htlc.amount_msat / 1000, &outp.per_commitment_point, &outp.htlc, &onchain_handler.secp_ctx) {
 426                                         let mut ser_sig = sig.serialize_der().to_vec();
 427                                         ser_sig.push(EcdsaSighashType::All as u8);
 428                                         bumped_tx.input[i].witness.push(ser_sig);
 429                                         bumped_tx.input[i].witness.push(outp.preimage.0.to_vec());
 430                                         bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
 431                                 }
 432                         },
 433                         PackageSolvingData::CounterpartyReceivedHTLCOutput(ref outp) => {
 434                                 let chan_keys = TxCreationKeys::derive_new(&onchain_handler.secp_ctx, &outp.per_commitment_point, &outp.counterparty_delayed_payment_base_key, &outp.counterparty_htlc_base_key, &onchain_handler.signer.pubkeys().revocation_basepoint, &onchain_handler.signer.pubkeys().htlc_basepoint);
 435                                 let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&outp.htlc, onchain_handler.opt_anchors(), &chan_keys.broadcaster_htlc_key, &chan_keys.countersignatory_htlc_key, &chan_keys.revocation_key);
 436
 437                                 bumped_tx.lock_time = PackedLockTime(outp.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
 438                                 if let Ok(sig) = onchain_handler.signer.sign_counterparty_htlc_transaction(&bumped_tx, i, &outp.htlc.amount_msat / 1000, &outp.per_commitment_point, &outp.htlc, &onchain_handler.secp_ctx) {
 439                                         let mut ser_sig = sig.serialize_der().to_vec();
 440                                         ser_sig.push(EcdsaSighashType::All as u8);
 441                                         bumped_tx.input[i].witness.push(ser_sig);
 442                                         // Due to BIP146 (MINIMALIF) this must be a zero-length element to relay.
 443                                         bumped_tx.input[i].witness.push(vec![]);
 444                                         bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
 445                                 }
 446                         },
 447                         _ => { panic!("API Error!"); }
 448                 }
 449                 true
 450         }
 451         fn get_finalized_tx<Signer: Sign>(&self, outpoint: &BitcoinOutPoint, onchain_handler: &mut OnchainTxHandler<Signer>) -> Option<Transaction> {
 452                 match self {
 453                         PackageSolvingData::HolderHTLCOutput(ref outp) => {
 454                                 debug_assert!(!outp.opt_anchors());
 455                                 return onchain_handler.get_fully_signed_htlc_tx(outpoint, &outp.preimage);
 456                         }
 457                         PackageSolvingData::HolderFundingOutput(ref outp) => {
 458                                 return Some(onchain_handler.get_fully_signed_holder_tx(&outp.funding_redeemscript));
 459                         }
 460                         _ => { panic!("API Error!"); }
 461                 }
 462         }
 463         fn absolute_tx_timelock(&self, output_conf_height: u32) -> u32 {
 464                 // Get the absolute timelock at which this output can be spent given the height at which
 465                 // this output was confirmed. We use `output_conf_height + 1` as a safe default as we can
 466                 // be confirmed in the next block and transactions with time lock `current_height + 1`
 467                 // always propagate.
 468                 let absolute_timelock = match self {
 469                         PackageSolvingData::RevokedOutput(_) => output_conf_height + 1,
 470                         PackageSolvingData::RevokedHTLCOutput(_) => output_conf_height + 1,
 471                         PackageSolvingData::CounterpartyOfferedHTLCOutput(_) => output_conf_height + 1,
 472                         PackageSolvingData::CounterpartyReceivedHTLCOutput(ref outp) => cmp::max(outp.htlc.cltv_expiry, output_conf_height + 1),
 473                         PackageSolvingData::HolderHTLCOutput(ref outp) => cmp::max(outp.cltv_expiry, output_conf_height + 1),
 474                         PackageSolvingData::HolderFundingOutput(_) => output_conf_height + 1,
 475                 };
 476                 absolute_timelock
 477         }
 478 }
 479
 480 impl_writeable_tlv_based_enum!(PackageSolvingData, ;
 481         (0, RevokedOutput),
 482         (1, RevokedHTLCOutput),
 483         (2, CounterpartyOfferedHTLCOutput),
 484         (3, CounterpartyReceivedHTLCOutput),
 485         (4, HolderHTLCOutput),
 486         (5, HolderFundingOutput),
 487 );
 488
 489 /// A malleable package might be aggregated with other packages to save on fees.
 490 /// A untractable package has been counter-signed and aggregable will break cached counterparty
 491 /// signatures.
 492 #[derive(Clone, PartialEq, Eq)]
 493 pub(crate) enum PackageMalleability {
 494         Malleable,
 495         Untractable,
 496 }
 497
 498 /// A structure to describe a package content that is generated by ChannelMonitor and
 499 /// used by OnchainTxHandler to generate and broadcast transactions settling onchain claims.
 500 ///
 501 /// A package is defined as one or more transactions claiming onchain outputs in reaction
 502 /// to confirmation of a channel transaction. Those packages might be aggregated to save on
 503 /// fees, if satisfaction of outputs's witnessScript let's us do so.
 504 ///
 505 /// As packages are time-sensitive, we fee-bump and rebroadcast them at scheduled intervals.
 506 /// Failing to confirm a package translate as a loss of funds for the user.
 507 #[derive(Clone, PartialEq, Eq)]
 508 pub struct PackageTemplate {
 509         // List of onchain outputs and solving data to generate satisfying witnesses.
 510         inputs: Vec<(BitcoinOutPoint, PackageSolvingData)>,
 511         // Packages are deemed as malleable if we have local knwoledge of at least one set of
 512         // private keys yielding a satisfying witnesses. Malleability implies that we can aggregate
 513         // packages among them to save on fees or rely on RBF to bump their feerates.
 514         // Untractable packages have been counter-signed and thus imply that we can't aggregate
 515         // them without breaking signatures. Fee-bumping strategy will also rely on CPFP.
 516         malleability: PackageMalleability,
 517         // Block height after which the earlier-output belonging to this package is mature for a
 518         // competing claim by the counterparty. As our chain tip becomes nearer from the timelock,
 519         // the fee-bumping frequency will increase. See `OnchainTxHandler::get_height_timer`.
 520         soonest_conf_deadline: u32,
 521         // Determines if this package can be aggregated.
 522         // Timelocked outputs belonging to the same transaction might have differing
 523         // satisfying heights. Picking up the later height among the output set would be a valid
 524         // aggregable strategy but it comes with at least 2 trade-offs :
 525         // * earlier-output fund are going to take longer to come back
 526         // * CLTV delta backing up a corresponding HTLC on an upstream channel could be swallowed
 527         // by the requirement of the later-output part of the set
 528         // For now, we mark such timelocked outputs as non-aggregable, though we might introduce
 529         // smarter aggregable strategy in the future.
 530         aggregable: bool,
 531         // Cache of package feerate committed at previous (re)broadcast. If bumping resources
 532         // (either claimed output value or external utxo), it will keep increasing until holder
 533         // or counterparty successful claim.
 534         feerate_previous: u64,
 535         // Cache of next height at which fee-bumping and rebroadcast will be attempted. In
 536         // the future, we might abstract it to an observed mempool fluctuation.
 537         height_timer: Option<u32>,
 538         // Confirmation height of the claimed outputs set transaction. In case of reorg reaching
 539         // it, we wipe out and forget the package.
 540         height_original: u32,
 541 }
 542
 543 impl PackageTemplate {
 544         pub(crate) fn is_malleable(&self) -> bool {
 545                 self.malleability == PackageMalleability::Malleable
 546         }
 547         pub(crate) fn timelock(&self) -> u32 {
 548                 self.soonest_conf_deadline
 549         }
 550         pub(crate) fn aggregable(&self) -> bool {
 551                 self.aggregable
 552         }
 553         pub(crate) fn set_feerate(&mut self, new_feerate: u64) {
 554                 self.feerate_previous = new_feerate;
 555         }
 556         pub(crate) fn timer(&self) -> Option<u32> {
 557                 if let Some(ref timer) = self.height_timer {
 558                         return Some(*timer);
 559                 }
 560                 None
 561         }
 562         pub(crate) fn set_timer(&mut self, new_timer: Option<u32>) {
 563                 self.height_timer = new_timer;
 564         }
 565         pub(crate) fn outpoints(&self) -> Vec<&BitcoinOutPoint> {
 566                 self.inputs.iter().map(|(o, _)| o).collect()
 567         }
 568         pub(crate) fn inputs(&self) -> impl ExactSizeIterator<Item = &PackageSolvingData> {
 569                 self.inputs.iter().map(|(_, i)| i)
 570         }
 571         pub(crate) fn split_package(&mut self, split_outp: &BitcoinOutPoint) -> Option<PackageTemplate> {
 572                 match self.malleability {
 573                         PackageMalleability::Malleable => {
 574                                 let mut split_package = None;
 575                                 let timelock = self.soonest_conf_deadline;
 576                                 let aggregable = self.aggregable;
 577                                 let feerate_previous = self.feerate_previous;
 578                                 let height_timer = self.height_timer;
 579                                 let height_original = self.height_original;
 580                                 self.inputs.retain(|outp| {
 581                                         if *split_outp == outp.0 {
 582                                                 split_package = Some(PackageTemplate {
 583                                                         inputs: vec![(outp.0, outp.1.clone())],
 584                                                         malleability: PackageMalleability::Malleable,
 585                                                         soonest_conf_deadline: timelock,
 586                                                         aggregable,
 587                                                         feerate_previous,
 588                                                         height_timer,
 589                                                         height_original,
 590                                                 });
 591                                                 return false;
 592                                         }
 593                                         return true;
 594                                 });
 595                                 return split_package;
 596                         },
 597                         _ => {
 598                                 // Note, we may try to split on remote transaction for
 599                                 // which we don't have a competing one (HTLC-Success before
 600                                 // timelock expiration). This explain we don't panic!
 601                                 // We should refactor OnchainTxHandler::block_connected to
 602                                 // only test equality on competing claims.
 603                                 return None;
 604                         }
 605                 }
 606         }
 607         pub(crate) fn merge_package(&mut self, mut merge_from: PackageTemplate) {
 608                 assert_eq!(self.height_original, merge_from.height_original);
 609                 if self.malleability == PackageMalleability::Untractable || merge_from.malleability == PackageMalleability::Untractable {
 610                         panic!("Merging template on untractable packages");
 611                 }
 612                 if !self.aggregable || !merge_from.aggregable {
 613                         panic!("Merging non aggregatable packages");
 614                 }
 615                 if let Some((_, lead_input)) = self.inputs.first() {
 616                         for (_, v) in merge_from.inputs.iter() {
 617                                 if !lead_input.is_compatible(v) { panic!("Merging outputs from differing types !"); }
 618                         }
 619                 } else { panic!("Merging template on an empty package"); }
 620                 for (k, v) in merge_from.inputs.drain(..) {
 621                         self.inputs.push((k, v));
 622                 }
 623                 //TODO: verify coverage and sanity?
 624                 if self.soonest_conf_deadline > merge_from.soonest_conf_deadline {
 625                         self.soonest_conf_deadline = merge_from.soonest_conf_deadline;
 626                 }
 627                 if self.feerate_previous > merge_from.feerate_previous {
 628                         self.feerate_previous = merge_from.feerate_previous;
 629                 }
 630                 self.height_timer = cmp::min(self.height_timer, merge_from.height_timer);
 631         }
 632         /// Gets the amount of all outptus being spent by this package, only valid for malleable
 633         /// packages.
 634         pub(crate) fn package_amount(&self) -> u64 {
 635                 let mut amounts = 0;
 636                 for (_, outp) in self.inputs.iter() {
 637                         amounts += outp.amount();
 638                 }
 639                 amounts
 640         }
 641         pub(crate) fn package_timelock(&self) -> u32 {
 642                 self.inputs.iter().map(|(_, outp)| outp.absolute_tx_timelock(self.height_original))
 643                         .max().expect("There must always be at least one output to spend in a PackageTemplate")
 644         }
 645         pub(crate) fn package_weight(&self, destination_script: &Script) -> usize {
 646                 let mut inputs_weight = 0;
 647                 let mut witnesses_weight = 2; // count segwit flags
 648                 for (_, outp) in self.inputs.iter() {
 649                         // previous_out_point: 36 bytes ; var_int: 1 byte ; sequence: 4 bytes
 650                         inputs_weight += 41 * WITNESS_SCALE_FACTOR;
 651                         witnesses_weight += outp.weight();
 652                 }
 653                 // version: 4 bytes ; count_tx_in: 1 byte ; count_tx_out: 1 byte ; lock_time: 4 bytes
 654                 let transaction_weight = 10 * WITNESS_SCALE_FACTOR;
 655                 // value: 8 bytes ; var_int: 1 byte ; pk_script: `destination_script.len()`
 656                 let output_weight = (8 + 1 + destination_script.len()) * WITNESS_SCALE_FACTOR;
 657                 inputs_weight + witnesses_weight + transaction_weight + output_weight
 658         }
 659         #[cfg(anchors)]
 660         pub(crate) fn construct_malleable_package_with_external_funding<Signer: Sign>(
 661                 &self, onchain_handler: &mut OnchainTxHandler<Signer>,
 662         ) -> Option<Vec<ExternalHTLCClaim>> {
 663                 debug_assert!(self.requires_external_funding());
 664                 let mut htlcs: Option<Vec<ExternalHTLCClaim>> = None;
 665                 for (previous_output, input) in &self.inputs {
 666                         match input {
 667                                 PackageSolvingData::HolderHTLCOutput(ref outp) => {
 668                                         debug_assert!(outp.opt_anchors());
 669                                         onchain_handler.generate_external_htlc_claim(&previous_output, &outp.preimage).map(|htlc| {
 670                                                 htlcs.get_or_insert_with(|| Vec::with_capacity(self.inputs.len())).push(htlc);
 671                                         });
 672                                 }
 673                                 _ => debug_assert!(false, "Expected HolderHTLCOutputs to not be aggregated with other input types"),
 674                         }
 675                 }
 676                 htlcs
 677         }
 678         pub(crate) fn finalize_malleable_package<L: Deref, Signer: Sign>(
 679                 &self, onchain_handler: &mut OnchainTxHandler<Signer>, value: u64, destination_script: Script, logger: &L
 680         ) -> Option<Transaction> where L::Target: Logger {
 681                 debug_assert!(self.is_malleable());
 682                 let mut bumped_tx = Transaction {
 683                         version: 2,
 684                         lock_time: PackedLockTime::ZERO,
 685                         input: vec![],
 686                         output: vec![TxOut {
 687                                 script_pubkey: destination_script,
 688                                 value,
 689                         }],
 690                 };
 691                 for (outpoint, _) in self.inputs.iter() {
 692                         bumped_tx.input.push(TxIn {
 693                                 previous_output: *outpoint,
 694                                 script_sig: Script::new(),
 695                                 sequence: Sequence::ENABLE_RBF_NO_LOCKTIME,
 696                                 witness: Witness::new(),
 697                         });
 698                 }
 699                 for (i, (outpoint, out)) in self.inputs.iter().enumerate() {
 700                         log_debug!(logger, "Adding claiming input for outpoint {}:{}", outpoint.txid, outpoint.vout);
 701                         if !out.finalize_input(&mut bumped_tx, i, onchain_handler) { return None; }
 702                 }
 703                 log_debug!(logger, "Finalized transaction {} ready to broadcast", bumped_tx.txid());
 704                 Some(bumped_tx)
 705         }
 706         pub(crate) fn finalize_untractable_package<L: Deref, Signer: Sign>(
 707                 &self, onchain_handler: &mut OnchainTxHandler<Signer>, logger: &L,
 708         ) -> Option<Transaction> where L::Target: Logger {
 709                 debug_assert!(!self.is_malleable());
 710                 if let Some((outpoint, outp)) = self.inputs.first() {
 711                         if let Some(final_tx) = outp.get_finalized_tx(outpoint, onchain_handler) {
 712                                 log_debug!(logger, "Adding claiming input for outpoint {}:{}", outpoint.txid, outpoint.vout);
 713                                 log_debug!(logger, "Finalized transaction {} ready to broadcast", final_tx.txid());
 714                                 return Some(final_tx);
 715                         }
 716                         return None;
 717                 } else { panic!("API Error: Package must not be inputs empty"); }
 718         }
 719         /// In LN, output claimed are time-sensitive, which means we have to spend them before reaching some timelock expiration. At in-channel
 720         /// 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
 721         /// height that once reached we should generate a new bumped "version" of the claim tx to be sure that we safely claim outputs before
 722         /// that our counterparty can do so. If timelock expires soon, height timer is going to be scaled down in consequence to increase
 723         /// frequency of the bump and so increase our bets of success.
 724         pub(crate) fn get_height_timer(&self, current_height: u32) -> u32 {
 725                 if self.soonest_conf_deadline <= current_height + MIDDLE_FREQUENCY_BUMP_INTERVAL {
 726                         return current_height + HIGH_FREQUENCY_BUMP_INTERVAL
 727                 } else if self.soonest_conf_deadline - current_height <= LOW_FREQUENCY_BUMP_INTERVAL {
 728                         return current_height + MIDDLE_FREQUENCY_BUMP_INTERVAL
 729                 }
 730                 current_height + LOW_FREQUENCY_BUMP_INTERVAL
 731         }
 732
 733         /// Returns value in satoshis to be included as package outgoing output amount and feerate
 734         /// which was used to generate the value. Will not return less than `dust_limit_sats` for the
 735         /// value.
 736         pub(crate) fn compute_package_output<F: Deref, L: Deref>(&self, predicted_weight: usize, dust_limit_sats: u64, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L) -> Option<(u64, u64)>
 737                 where F::Target: FeeEstimator,
 738                       L::Target: Logger,
 739         {
 740                 debug_assert!(self.malleability == PackageMalleability::Malleable, "The package output is fixed for non-malleable packages");
 741                 let input_amounts = self.package_amount();
 742                 assert!(dust_limit_sats as i64 > 0, "Output script must be broadcastable/have a 'real' dust limit.");
 743                 // If old feerate is 0, first iteration of this claim, use normal fee calculation
 744                 if self.feerate_previous != 0 {
 745                         if let Some((new_fee, feerate)) = feerate_bump(predicted_weight, input_amounts, self.feerate_previous, fee_estimator, logger) {
 746                                 return Some((cmp::max(input_amounts as i64 - new_fee as i64, dust_limit_sats as i64) as u64, feerate));
 747                         }
 748                 } else {
 749                         if let Some((new_fee, feerate)) = compute_fee_from_spent_amounts(input_amounts, predicted_weight, fee_estimator, logger) {
 750                                 return Some((cmp::max(input_amounts as i64 - new_fee as i64, dust_limit_sats as i64) as u64, feerate));
 751                         }
 752                 }
 753                 None
 754         }
 755
 756         #[cfg(anchors)]
 757         /// Computes a feerate based on the given confirmation target. If a previous feerate was used,
 758         /// and the new feerate is below it, we'll use a 25% increase of the previous feerate instead of
 759         /// the new one.
 760         pub(crate) fn compute_package_feerate<F: Deref>(
 761                 &self, fee_estimator: &LowerBoundedFeeEstimator<F>, conf_target: ConfirmationTarget,
 762         ) -> u32 where F::Target: FeeEstimator {
 763                 let feerate_estimate = fee_estimator.bounded_sat_per_1000_weight(conf_target);
 764                 if self.feerate_previous != 0 {
 765                         // If old feerate inferior to actual one given back by Fee Estimator, use it to compute new fee...
 766                         if feerate_estimate as u64 > self.feerate_previous {
 767                                 feerate_estimate
 768                         } else {
 769                                 // ...else just increase the previous feerate by 25% (because that's a nice number)
 770                                 (self.feerate_previous + (self.feerate_previous / 4)).try_into().unwrap_or(u32::max_value())
 771                         }
 772                 } else {
 773                         feerate_estimate
 774                 }
 775         }
 776
 777         /// Determines whether a package contains an input which must have additional external inputs
 778         /// attached to help the spending transaction reach confirmation.
 779         pub(crate) fn requires_external_funding(&self) -> bool {
 780                 self.inputs.iter().find(|input| match input.1 {
 781                         PackageSolvingData::HolderFundingOutput(ref outp) => outp.opt_anchors(),
 782                         PackageSolvingData::HolderHTLCOutput(ref outp) => outp.opt_anchors(),
 783                         _ => false,
 784                 }).is_some()
 785         }
 786
 787         pub (crate) fn build_package(txid: Txid, vout: u32, input_solving_data: PackageSolvingData, soonest_conf_deadline: u32, aggregable: bool, height_original: u32) -> Self {
 788                 let malleability = match input_solving_data {
 789                         PackageSolvingData::RevokedOutput(..) => PackageMalleability::Malleable,
 790                         PackageSolvingData::RevokedHTLCOutput(..) => PackageMalleability::Malleable,
 791                         PackageSolvingData::CounterpartyOfferedHTLCOutput(..) => PackageMalleability::Malleable,
 792                         PackageSolvingData::CounterpartyReceivedHTLCOutput(..) => PackageMalleability::Malleable,
 793                         PackageSolvingData::HolderHTLCOutput(ref outp) => if outp.opt_anchors() {
 794                                 PackageMalleability::Malleable
 795                         } else {
 796                                 PackageMalleability::Untractable
 797                         },
 798                         PackageSolvingData::HolderFundingOutput(..) => PackageMalleability::Untractable,
 799                 };
 800                 let mut inputs = Vec::with_capacity(1);
 801                 inputs.push((BitcoinOutPoint { txid, vout }, input_solving_data));
 802                 PackageTemplate {
 803                         inputs,
 804                         malleability,
 805                         soonest_conf_deadline,
 806                         aggregable,
 807                         feerate_previous: 0,
 808                         height_timer: None,
 809                         height_original,
 810                 }
 811         }
 812 }
 813
 814 impl Writeable for PackageTemplate {
 815         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 816                 writer.write_all(&(self.inputs.len() as u64).to_be_bytes())?;
 817                 for (ref outpoint, ref rev_outp) in self.inputs.iter() {
 818                         outpoint.write(writer)?;
 819                         rev_outp.write(writer)?;
 820                 }
 821                 write_tlv_fields!(writer, {
 822                         (0, self.soonest_conf_deadline, required),
 823                         (2, self.feerate_previous, required),
 824                         (4, self.height_original, required),
 825                         (6, self.height_timer, option)
 826                 });
 827                 Ok(())
 828         }
 829 }
 830
 831 impl Readable for PackageTemplate {
 832         fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
 833                 let inputs_count = <u64 as Readable>::read(reader)?;
 834                 let mut inputs: Vec<(BitcoinOutPoint, PackageSolvingData)> = Vec::with_capacity(cmp::min(inputs_count as usize, MAX_ALLOC_SIZE / 128));
 835                 for _ in 0..inputs_count {
 836                         let outpoint = Readable::read(reader)?;
 837                         let rev_outp = Readable::read(reader)?;
 838                         inputs.push((outpoint, rev_outp));
 839                 }
 840                 let (malleability, aggregable) = if let Some((_, lead_input)) = inputs.first() {
 841                         match lead_input {
 842                                 PackageSolvingData::RevokedOutput(..) => { (PackageMalleability::Malleable, true) },
 843                                 PackageSolvingData::RevokedHTLCOutput(..) => { (PackageMalleability::Malleable, true) },
 844                                 PackageSolvingData::CounterpartyOfferedHTLCOutput(..) => { (PackageMalleability::Malleable, true) },
 845                                 PackageSolvingData::CounterpartyReceivedHTLCOutput(..) => { (PackageMalleability::Malleable, false) },
 846                                 PackageSolvingData::HolderHTLCOutput(ref outp) => if outp.opt_anchors() {
 847                                         (PackageMalleability::Malleable, outp.preimage.is_some())
 848                                 } else {
 849                                         (PackageMalleability::Untractable, false)
 850                                 },
 851                                 PackageSolvingData::HolderFundingOutput(..) => { (PackageMalleability::Untractable, false) },
 852                         }
 853                 } else { return Err(DecodeError::InvalidValue); };
 854                 let mut soonest_conf_deadline = 0;
 855                 let mut feerate_previous = 0;
 856                 let mut height_timer = None;
 857                 let mut height_original = 0;
 858                 read_tlv_fields!(reader, {
 859                         (0, soonest_conf_deadline, required),
 860                         (2, feerate_previous, required),
 861                         (4, height_original, required),
 862                         (6, height_timer, option),
 863                 });
 864                 Ok(PackageTemplate {
 865                         inputs,
 866                         malleability,
 867                         soonest_conf_deadline,
 868                         aggregable,
 869                         feerate_previous,
 870                         height_timer,
 871                         height_original,
 872                 })
 873         }
 874 }
 875
 876 /// Attempt to propose a bumping fee for a transaction from its spent output's values and predicted
 877 /// weight. We start with the highest priority feerate returned by the node's fee estimator then
 878 /// fall-back to lower priorities until we have enough value available to suck from.
 879 ///
 880 /// If the proposed fee is less than the available spent output's values, we return the proposed
 881 /// fee and the corresponding updated feerate. If the proposed fee is equal or more than the
 882 /// available spent output's values, we return nothing
 883 fn compute_fee_from_spent_amounts<F: Deref, L: Deref>(input_amounts: u64, predicted_weight: usize, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L) -> Option<(u64, u64)>
 884         where F::Target: FeeEstimator,
 885               L::Target: Logger,
 886 {
 887         let mut updated_feerate = fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::HighPriority) as u64;
 888         let mut fee = updated_feerate * (predicted_weight as u64) / 1000;
 889         if input_amounts <= fee {
 890                 updated_feerate = fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Normal) as u64;
 891                 fee = updated_feerate * (predicted_weight as u64) / 1000;
 892                 if input_amounts <= fee {
 893                         updated_feerate = fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Background) as u64;
 894                         fee = updated_feerate * (predicted_weight as u64) / 1000;
 895                         if input_amounts <= fee {
 896                                 log_error!(logger, "Failed to generate an on-chain punishment tx as even low priority fee ({} sat) was more than the entire claim balance ({} sat)",
 897                                         fee, input_amounts);
 898                                 None
 899                         } else {
 900                                 log_warn!(logger, "Used low priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
 901                                         input_amounts);
 902                                 Some((fee, updated_feerate))
 903                         }
 904                 } else {
 905                         log_warn!(logger, "Used medium priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
 906                                 input_amounts);
 907                         Some((fee, updated_feerate))
 908                 }
 909         } else {
 910                 Some((fee, updated_feerate))
 911         }
 912 }
 913
 914 /// Attempt to propose a bumping fee for a transaction from its spent output's values and predicted
 915 /// weight. If feerates proposed by the fee-estimator have been increasing since last fee-bumping
 916 /// attempt, use them. Otherwise, blindly bump the feerate by 25% of the previous feerate. We also
 917 /// verify that those bumping heuristics respect BIP125 rules 3) and 4) and if required adjust
 918 /// the new fee to meet the RBF policy requirement.
 919 fn feerate_bump<F: Deref, L: Deref>(predicted_weight: usize, input_amounts: u64, previous_feerate: u64, fee_estimator: &LowerBoundedFeeEstimator<F>, logger: &L) -> Option<(u64, u64)>
 920         where F::Target: FeeEstimator,
 921               L::Target: Logger,
 922 {
 923         // If old feerate inferior to actual one given back by Fee Estimator, use it to compute new fee...
 924         let new_fee = if let Some((new_fee, _)) = compute_fee_from_spent_amounts(input_amounts, predicted_weight, fee_estimator, logger) {
 925                 let updated_feerate = new_fee / (predicted_weight as u64 * 1000);
 926                 if updated_feerate > previous_feerate {
 927                         new_fee
 928                 } else {
 929                         // ...else just increase the previous feerate by 25% (because that's a nice number)
 930                         let new_fee = previous_feerate * (predicted_weight as u64) / 750;
 931                         if input_amounts <= new_fee {
 932                                 log_warn!(logger, "Can't 25% bump new claiming tx, amount {} is too small", input_amounts);
 933                                 return None;
 934                         }
 935                         new_fee
 936                 }
 937         } else {
 938                 log_warn!(logger, "Can't new-estimation bump new claiming tx, amount {} is too small", input_amounts);
 939                 return None;
 940         };
 941
 942         let previous_fee = previous_feerate * (predicted_weight as u64) / 1000;
 943         let min_relay_fee = MIN_RELAY_FEE_SAT_PER_1000_WEIGHT * (predicted_weight as u64) / 1000;
 944         // BIP 125 Opt-in Full Replace-by-Fee Signaling
 945         //      * 3. The replacement transaction pays an absolute fee of at least the sum paid by the original transactions.
 946         //      * 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.
 947         let new_fee = if new_fee < previous_fee + min_relay_fee {
 948                 new_fee + previous_fee + min_relay_fee - new_fee
 949         } else {
 950                 new_fee
 951         };
 952         Some((new_fee, new_fee * 1000 / (predicted_weight as u64)))
 953 }
 954
 955 #[cfg(test)]
 956 mod tests {
 957         use crate::chain::package::{CounterpartyOfferedHTLCOutput, CounterpartyReceivedHTLCOutput, HolderHTLCOutput, PackageTemplate, PackageSolvingData, RevokedOutput, WEIGHT_REVOKED_OUTPUT, weight_offered_htlc, weight_received_htlc};
 958         use crate::chain::Txid;
 959         use crate::ln::chan_utils::HTLCOutputInCommitment;
 960         use crate::ln::{PaymentPreimage, PaymentHash};
 961
 962         use bitcoin::blockdata::constants::WITNESS_SCALE_FACTOR;
 963         use bitcoin::blockdata::script::Script;
 964         use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
 965
 966         use bitcoin::hashes::hex::FromHex;
 967
 968         use bitcoin::secp256k1::{PublicKey,SecretKey};
 969         use bitcoin::secp256k1::Secp256k1;
 970
 971         macro_rules! dumb_revk_output {
 972                 ($secp_ctx: expr) => {
 973                         {
 974                                 let dumb_scalar = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
 975                                 let dumb_point = PublicKey::from_secret_key(&$secp_ctx, &dumb_scalar);
 976                                 PackageSolvingData::RevokedOutput(RevokedOutput::build(dumb_point, dumb_point, dumb_point, dumb_scalar, 0, 0))
 977                         }
 978                 }
 979         }
 980
 981         macro_rules! dumb_counterparty_output {
 982                 ($secp_ctx: expr, $amt: expr, $opt_anchors: expr) => {
 983                         {
 984                                 let dumb_scalar = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
 985                                 let dumb_point = PublicKey::from_secret_key(&$secp_ctx, &dumb_scalar);
 986                                 let hash = PaymentHash([1; 32]);
 987                                 let htlc = HTLCOutputInCommitment { offered: true, amount_msat: $amt, cltv_expiry: 0, payment_hash: hash, transaction_output_index: None };
 988                                 PackageSolvingData::CounterpartyReceivedHTLCOutput(CounterpartyReceivedHTLCOutput::build(dumb_point, dumb_point, dumb_point, htlc, $opt_anchors))
 989                         }
 990                 }
 991         }
 992
 993         macro_rules! dumb_counterparty_offered_output {
 994                 ($secp_ctx: expr, $amt: expr, $opt_anchors: expr) => {
 995                         {
 996                                 let dumb_scalar = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
 997                                 let dumb_point = PublicKey::from_secret_key(&$secp_ctx, &dumb_scalar);
 998                                 let hash = PaymentHash([1; 32]);
 999                                 let preimage = PaymentPreimage([2;32]);
1000                                 let htlc = HTLCOutputInCommitment { offered: false, amount_msat: $amt, cltv_expiry: 1000, payment_hash: hash, transaction_output_index: None };
1001                                 PackageSolvingData::CounterpartyOfferedHTLCOutput(CounterpartyOfferedHTLCOutput::build(dumb_point, dumb_point, dumb_point, preimage, htlc, $opt_anchors))
1002                         }
1003                 }
1004         }
1005
1006         macro_rules! dumb_htlc_output {
1007                 () => {
1008                         {
1009                                 let preimage = PaymentPreimage([2;32]);
1010                                 PackageSolvingData::HolderHTLCOutput(HolderHTLCOutput::build_accepted(preimage, 0, false))
1011                         }
1012                 }
1013         }
1014
1015         #[test]
1016         #[should_panic]
1017         fn test_package_differing_heights() {
1018                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1019                 let secp_ctx = Secp256k1::new();
1020                 let revk_outp = dumb_revk_output!(secp_ctx);
1021
1022                 let mut package_one_hundred = PackageTemplate::build_package(txid, 0, revk_outp.clone(), 1000, true, 100);
1023                 let package_two_hundred = PackageTemplate::build_package(txid, 1, revk_outp.clone(), 1000, true, 200);
1024                 package_one_hundred.merge_package(package_two_hundred);
1025         }
1026
1027         #[test]
1028         #[should_panic]
1029         fn test_package_untractable_merge_to() {
1030                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1031                 let secp_ctx = Secp256k1::new();
1032                 let revk_outp = dumb_revk_output!(secp_ctx);
1033                 let htlc_outp = dumb_htlc_output!();
1034
1035                 let mut untractable_package = PackageTemplate::build_package(txid, 0, revk_outp.clone(), 1000, true, 100);
1036                 let malleable_package = PackageTemplate::build_package(txid, 1, htlc_outp.clone(), 1000, true, 100);
1037                 untractable_package.merge_package(malleable_package);
1038         }
1039
1040         #[test]
1041         #[should_panic]
1042         fn test_package_untractable_merge_from() {
1043                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1044                 let secp_ctx = Secp256k1::new();
1045                 let htlc_outp = dumb_htlc_output!();
1046                 let revk_outp = dumb_revk_output!(secp_ctx);
1047
1048                 let mut malleable_package = PackageTemplate::build_package(txid, 0, htlc_outp.clone(), 1000, true, 100);
1049                 let untractable_package = PackageTemplate::build_package(txid, 1, revk_outp.clone(), 1000, true, 100);
1050                 malleable_package.merge_package(untractable_package);
1051         }
1052
1053         #[test]
1054         #[should_panic]
1055         fn test_package_noaggregation_to() {
1056                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1057                 let secp_ctx = Secp256k1::new();
1058                 let revk_outp = dumb_revk_output!(secp_ctx);
1059
1060                 let mut noaggregation_package = PackageTemplate::build_package(txid, 0, revk_outp.clone(), 1000, false, 100);
1061                 let aggregation_package = PackageTemplate::build_package(txid, 1, revk_outp.clone(), 1000, true, 100);
1062                 noaggregation_package.merge_package(aggregation_package);
1063         }
1064
1065         #[test]
1066         #[should_panic]
1067         fn test_package_noaggregation_from() {
1068                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1069                 let secp_ctx = Secp256k1::new();
1070                 let revk_outp = dumb_revk_output!(secp_ctx);
1071
1072                 let mut aggregation_package = PackageTemplate::build_package(txid, 0, revk_outp.clone(), 1000, true, 100);
1073                 let noaggregation_package = PackageTemplate::build_package(txid, 1, revk_outp.clone(), 1000, false, 100);
1074                 aggregation_package.merge_package(noaggregation_package);
1075         }
1076
1077         #[test]
1078         #[should_panic]
1079         fn test_package_empty() {
1080                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1081                 let secp_ctx = Secp256k1::new();
1082                 let revk_outp = dumb_revk_output!(secp_ctx);
1083
1084                 let mut empty_package = PackageTemplate::build_package(txid, 0, revk_outp.clone(), 1000, true, 100);
1085                 empty_package.inputs = vec![];
1086                 let package = PackageTemplate::build_package(txid, 1, revk_outp.clone(), 1000, true, 100);
1087                 empty_package.merge_package(package);
1088         }
1089
1090         #[test]
1091         #[should_panic]
1092         fn test_package_differing_categories() {
1093                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1094                 let secp_ctx = Secp256k1::new();
1095                 let revk_outp = dumb_revk_output!(secp_ctx);
1096                 let counterparty_outp = dumb_counterparty_output!(secp_ctx, 0, false);
1097
1098                 let mut revoked_package = PackageTemplate::build_package(txid, 0, revk_outp, 1000, true, 100);
1099                 let counterparty_package = PackageTemplate::build_package(txid, 1, counterparty_outp, 1000, true, 100);
1100                 revoked_package.merge_package(counterparty_package);
1101         }
1102
1103         #[test]
1104         fn test_package_split_malleable() {
1105                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1106                 let secp_ctx = Secp256k1::new();
1107                 let revk_outp_one = dumb_revk_output!(secp_ctx);
1108                 let revk_outp_two = dumb_revk_output!(secp_ctx);
1109                 let revk_outp_three = dumb_revk_output!(secp_ctx);
1110
1111                 let mut package_one = PackageTemplate::build_package(txid, 0, revk_outp_one, 1000, true, 100);
1112                 let package_two = PackageTemplate::build_package(txid, 1, revk_outp_two, 1000, true, 100);
1113                 let package_three = PackageTemplate::build_package(txid, 2, revk_outp_three, 1000, true, 100);
1114
1115                 package_one.merge_package(package_two);
1116                 package_one.merge_package(package_three);
1117                 assert_eq!(package_one.outpoints().len(), 3);
1118
1119                 if let Some(split_package) = package_one.split_package(&BitcoinOutPoint { txid, vout: 1 }) {
1120                         // Packages attributes should be identical
1121                         assert!(split_package.is_malleable());
1122                         assert_eq!(split_package.soonest_conf_deadline, package_one.soonest_conf_deadline);
1123                         assert_eq!(split_package.aggregable, package_one.aggregable);
1124                         assert_eq!(split_package.feerate_previous, package_one.feerate_previous);
1125                         assert_eq!(split_package.height_timer, package_one.height_timer);
1126                         assert_eq!(split_package.height_original, package_one.height_original);
1127                 } else { panic!(); }
1128                 assert_eq!(package_one.outpoints().len(), 2);
1129         }
1130
1131         #[test]
1132         fn test_package_split_untractable() {
1133                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1134                 let htlc_outp_one = dumb_htlc_output!();
1135
1136                 let mut package_one = PackageTemplate::build_package(txid, 0, htlc_outp_one, 1000, true, 100);
1137                 let ret_split = package_one.split_package(&BitcoinOutPoint { txid, vout: 0});
1138                 assert!(ret_split.is_none());
1139         }
1140
1141         #[test]
1142         fn test_package_timer() {
1143                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1144                 let secp_ctx = Secp256k1::new();
1145                 let revk_outp = dumb_revk_output!(secp_ctx);
1146
1147                 let mut package = PackageTemplate::build_package(txid, 0, revk_outp, 1000, true, 100);
1148                 let timer_none = package.timer();
1149                 assert!(timer_none.is_none());
1150                 package.set_timer(Some(100));
1151                 if let Some(timer_some) = package.timer() {
1152                         assert_eq!(timer_some, 100);
1153                 } else { panic!() }
1154         }
1155
1156         #[test]
1157         fn test_package_amounts() {
1158                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1159                 let secp_ctx = Secp256k1::new();
1160                 let counterparty_outp = dumb_counterparty_output!(secp_ctx, 1_000_000, false);
1161
1162                 let package = PackageTemplate::build_package(txid, 0, counterparty_outp, 1000, true, 100);
1163                 assert_eq!(package.package_amount(), 1000);
1164         }
1165
1166         #[test]
1167         fn test_package_weight() {
1168                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1169                 let secp_ctx = Secp256k1::new();
1170
1171                 // (nVersion (4) + nLocktime (4) + count_tx_in (1) + prevout (36) + sequence (4) + script_length (1) + count_tx_out (1) + value (8) + var_int (1)) * WITNESS_SCALE_FACTOR + witness marker (2)
1172                 let weight_sans_output = (4 + 4 + 1 + 36 + 4 + 1 + 1 + 8 + 1) * WITNESS_SCALE_FACTOR + 2;
1173
1174                 {
1175                         let revk_outp = dumb_revk_output!(secp_ctx);
1176                         let package = PackageTemplate::build_package(txid, 0, revk_outp, 0, true, 100);
1177                         assert_eq!(package.package_weight(&Script::new()),  weight_sans_output + WEIGHT_REVOKED_OUTPUT as usize);
1178                 }
1179
1180                 {
1181                         for &opt_anchors in [false, true].iter() {
1182                                 let counterparty_outp = dumb_counterparty_output!(secp_ctx, 1_000_000, opt_anchors);
1183                                 let package = PackageTemplate::build_package(txid, 0, counterparty_outp, 1000, true, 100);
1184                                 assert_eq!(package.package_weight(&Script::new()), weight_sans_output + weight_received_htlc(opt_anchors) as usize);
1185                         }
1186                 }
1187
1188                 {
1189                         for &opt_anchors in [false, true].iter() {
1190                                 let counterparty_outp = dumb_counterparty_offered_output!(secp_ctx, 1_000_000, opt_anchors);
1191                                 let package = PackageTemplate::build_package(txid, 0, counterparty_outp, 1000, true, 100);
1192                                 assert_eq!(package.package_weight(&Script::new()), weight_sans_output + weight_offered_htlc(opt_anchors) as usize);
1193                         }
1194                 }
1195         }
1196 }