_ 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 use crate::chain::onchaintx::OnchainTxHandler;
  30 use crate::util::byte_utils;
  31 use crate::util::logger::Logger;
  32 use crate::util::ser::{Readable, Writer, Writeable};
  33
  34 use crate::io;
  35 use crate::prelude::*;
  36 use core::cmp;
  37 #[cfg(anchors)]
  38 use core::convert::TryInto;
  39 use core::mem;
  40 use core::ops::Deref;
  41 use bitcoin::{PackedLockTime, Sequence, Witness};
  42
  43 use super::chaininterface::LowerBoundedFeeEstimator;
  44
  45 const MAX_ALLOC_SIZE: usize = 64*1024;
  46
  47
  48 pub(crate) fn weight_revoked_offered_htlc(opt_anchors: bool) -> u64 {
  49         // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
  50         const WEIGHT_REVOKED_OFFERED_HTLC: u64 = 1 + 1 + 73 + 1 + 33 + 1 + 133;
  51         const WEIGHT_REVOKED_OFFERED_HTLC_ANCHORS: u64 = WEIGHT_REVOKED_OFFERED_HTLC + 3; // + OP_1 + OP_CSV + OP_DROP
  52         if opt_anchors { WEIGHT_REVOKED_OFFERED_HTLC_ANCHORS } else { WEIGHT_REVOKED_OFFERED_HTLC }
  53 }
  54
  55 pub(crate) fn weight_revoked_received_htlc(opt_anchors: bool) -> u64 {
  56         // number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
  57         const WEIGHT_REVOKED_RECEIVED_HTLC: u64 = 1 + 1 + 73 + 1 + 33 + 1 +  139;
  58         const WEIGHT_REVOKED_RECEIVED_HTLC_ANCHORS: u64 = WEIGHT_REVOKED_RECEIVED_HTLC + 3; // + OP_1 + OP_CSV + OP_DROP
  59         if opt_anchors { WEIGHT_REVOKED_RECEIVED_HTLC_ANCHORS } else { WEIGHT_REVOKED_RECEIVED_HTLC }
  60 }
  61
  62 pub(crate) fn weight_offered_htlc(opt_anchors: bool) -> u64 {
  63         // number_of_witness_elements + sig_length + counterpartyhtlc_sig  + preimage_length + preimage + witness_script_length + witness_script
  64         const WEIGHT_OFFERED_HTLC: u64 = 1 + 1 + 73 + 1 + 32 + 1 + 133;
  65         const WEIGHT_OFFERED_HTLC_ANCHORS: u64 = WEIGHT_OFFERED_HTLC + 3; // + OP_1 + OP_CSV + OP_DROP
  66         if opt_anchors { WEIGHT_OFFERED_HTLC_ANCHORS } else { WEIGHT_OFFERED_HTLC }
  67 }
  68
  69 pub(crate) fn weight_received_htlc(opt_anchors: bool) -> u64 {
  70         // number_of_witness_elements + sig_length + counterpartyhtlc_sig + empty_vec_length + empty_vec + witness_script_length + witness_script
  71         const WEIGHT_RECEIVED_HTLC: u64 = 1 + 1 + 73 + 1 + 1 + 1 + 139;
  72         const WEIGHT_RECEIVED_HTLC_ANCHORS: u64 = WEIGHT_RECEIVED_HTLC + 3; // + OP_1 + OP_CSV + OP_DROP
  73         if opt_anchors { WEIGHT_RECEIVED_HTLC_ANCHORS } else { WEIGHT_RECEIVED_HTLC }
  74 }
  75
  76 // number_of_witness_elements + sig_length + revocation_sig + true_length + op_true + witness_script_length + witness_script
  77 pub(crate) const WEIGHT_REVOKED_OUTPUT: u64 = 1 + 1 + 73 + 1 + 1 + 1 + 77;
  78
  79 /// Height delay at which transactions are fee-bumped/rebroadcasted with a low priority.
  80 const LOW_FREQUENCY_BUMP_INTERVAL: u32 = 15;
  81 /// Height delay at which transactions are fee-bumped/rebroadcasted with a middle priority.
  82 const MIDDLE_FREQUENCY_BUMP_INTERVAL: u32 = 3;
  83 /// Height delay at which transactions are fee-bumped/rebroadcasted with a high priority.
  84 const HIGH_FREQUENCY_BUMP_INTERVAL: u32 = 1;
  85
  86 /// A struct to describe a revoked output and corresponding information to generate a solving
  87 /// witness spending a commitment `to_local` output or a second-stage HTLC transaction output.
  88 ///
  89 /// CSV and pubkeys are used as part of a witnessScript redeeming a balance output, amount is used
  90 /// as part of the signature hash and revocation secret to generate a satisfying witness.
  91 #[derive(Clone, PartialEq, Eq)]
  92 pub(crate) struct RevokedOutput {
  93         per_commitment_point: PublicKey,
  94         counterparty_delayed_payment_base_key: PublicKey,
  95         counterparty_htlc_base_key: PublicKey,
  96         per_commitment_key: SecretKey,
  97         weight: u64,
  98         amount: u64,
  99         on_counterparty_tx_csv: u16,
 100 }
 101
 102 impl RevokedOutput {
 103         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 {
 104                 RevokedOutput {
 105                         per_commitment_point,
 106                         counterparty_delayed_payment_base_key,
 107                         counterparty_htlc_base_key,
 108                         per_commitment_key,
 109                         weight: WEIGHT_REVOKED_OUTPUT,
 110                         amount,
 111                         on_counterparty_tx_csv
 112                 }
 113         }
 114 }
 115
 116 impl_writeable_tlv_based!(RevokedOutput, {
 117         (0, per_commitment_point, required),
 118         (2, counterparty_delayed_payment_base_key, required),
 119         (4, counterparty_htlc_base_key, required),
 120         (6, per_commitment_key, required),
 121         (8, weight, required),
 122         (10, amount, required),
 123         (12, on_counterparty_tx_csv, required),
 124 });
 125
 126 /// A struct to describe a revoked offered output and corresponding information to generate a
 127 /// solving witness.
 128 ///
 129 /// HTLCOuputInCommitment (hash timelock, direction) and pubkeys are used to generate a suitable
 130 /// witnessScript.
 131 ///
 132 /// CSV is used as part of a witnessScript redeeming a balance output, amount is used as part
 133 /// of the signature hash and revocation secret to generate a satisfying witness.
 134 #[derive(Clone, PartialEq, Eq)]
 135 pub(crate) struct RevokedHTLCOutput {
 136         per_commitment_point: PublicKey,
 137         counterparty_delayed_payment_base_key: PublicKey,
 138         counterparty_htlc_base_key: PublicKey,
 139         per_commitment_key: SecretKey,
 140         weight: u64,
 141         amount: u64,
 142         htlc: HTLCOutputInCommitment,
 143 }
 144
 145 impl RevokedHTLCOutput {
 146         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 {
 147                 let weight = if htlc.offered { weight_revoked_offered_htlc(opt_anchors) } else { weight_revoked_received_htlc(opt_anchors) };
 148                 RevokedHTLCOutput {
 149                         per_commitment_point,
 150                         counterparty_delayed_payment_base_key,
 151                         counterparty_htlc_base_key,
 152                         per_commitment_key,
 153                         weight,
 154                         amount,
 155                         htlc
 156                 }
 157         }
 158 }
 159
 160 impl_writeable_tlv_based!(RevokedHTLCOutput, {
 161         (0, per_commitment_point, required),
 162         (2, counterparty_delayed_payment_base_key, required),
 163         (4, counterparty_htlc_base_key, required),
 164         (6, per_commitment_key, required),
 165         (8, weight, required),
 166         (10, amount, required),
 167         (12, htlc, required),
 168 });
 169
 170 /// A struct to describe a HTLC output on a counterparty commitment transaction.
 171 ///
 172 /// HTLCOutputInCommitment (hash, timelock, directon) and pubkeys are used to generate a suitable
 173 /// witnessScript.
 174 ///
 175 /// The preimage is used as part of the witness.
 176 #[derive(Clone, PartialEq, Eq)]
 177 pub(crate) struct CounterpartyOfferedHTLCOutput {
 178         per_commitment_point: PublicKey,
 179         counterparty_delayed_payment_base_key: PublicKey,
 180         counterparty_htlc_base_key: PublicKey,
 181         preimage: PaymentPreimage,
 182         htlc: HTLCOutputInCommitment,
 183         opt_anchors: Option<()>,
 184 }
 185
 186 impl CounterpartyOfferedHTLCOutput {
 187         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 {
 188                 CounterpartyOfferedHTLCOutput {
 189                         per_commitment_point,
 190                         counterparty_delayed_payment_base_key,
 191                         counterparty_htlc_base_key,
 192                         preimage,
 193                         htlc,
 194                         opt_anchors: if opt_anchors { Some(()) } else { None },
 195                 }
 196         }
 197
 198         fn opt_anchors(&self) -> bool {
 199                 self.opt_anchors.is_some()
 200         }
 201 }
 202
 203 impl_writeable_tlv_based!(CounterpartyOfferedHTLCOutput, {
 204         (0, per_commitment_point, required),
 205         (1, opt_anchors, option),
 206         (2, counterparty_delayed_payment_base_key, required),
 207         (4, counterparty_htlc_base_key, required),
 208         (6, preimage, required),
 209         (8, htlc, required),
 210 });
 211
 212 /// A struct to describe a HTLC output on a counterparty commitment transaction.
 213 ///
 214 /// HTLCOutputInCommitment (hash, timelock, directon) and pubkeys are used to generate a suitable
 215 /// witnessScript.
 216 #[derive(Clone, PartialEq, Eq)]
 217 pub(crate) struct CounterpartyReceivedHTLCOutput {
 218         per_commitment_point: PublicKey,
 219         counterparty_delayed_payment_base_key: PublicKey,
 220         counterparty_htlc_base_key: PublicKey,
 221         htlc: HTLCOutputInCommitment,
 222         opt_anchors: Option<()>,
 223 }
 224
 225 impl CounterpartyReceivedHTLCOutput {
 226         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 {
 227                 CounterpartyReceivedHTLCOutput {
 228                         per_commitment_point,
 229                         counterparty_delayed_payment_base_key,
 230                         counterparty_htlc_base_key,
 231                         htlc,
 232                         opt_anchors: if opt_anchors { Some(()) } else { None },
 233                 }
 234         }
 235
 236         fn opt_anchors(&self) -> bool {
 237                 self.opt_anchors.is_some()
 238         }
 239 }
 240
 241 impl_writeable_tlv_based!(CounterpartyReceivedHTLCOutput, {
 242         (0, per_commitment_point, required),
 243         (1, opt_anchors, option),
 244         (2, counterparty_delayed_payment_base_key, required),
 245         (4, counterparty_htlc_base_key, required),
 246         (6, htlc, required),
 247 });
 248
 249 /// A struct to describe a HTLC output on holder commitment transaction.
 250 ///
 251 /// Either offered or received, the amount is always used as part of the bip143 sighash.
 252 /// Preimage is only included as part of the witness in former case.
 253 #[derive(Clone, PartialEq, Eq)]
 254 pub(crate) struct HolderHTLCOutput {
 255         preimage: Option<PaymentPreimage>,
 256         amount: u64,
 257         /// Defaults to 0 for HTLC-Success transactions, which have no expiry
 258         cltv_expiry: u32,
 259 }
 260
 261 impl HolderHTLCOutput {
 262         pub(crate) fn build_offered(amount: u64, cltv_expiry: u32) -> Self {
 263                 HolderHTLCOutput {
 264                         preimage: None,
 265                         amount,
 266                         cltv_expiry,
 267                 }
 268         }
 269
 270         pub(crate) fn build_accepted(preimage: PaymentPreimage, amount: u64) -> Self {
 271                 HolderHTLCOutput {
 272                         preimage: Some(preimage),
 273                         amount,
 274                         cltv_expiry: 0,
 275                 }
 276         }
 277 }
 278
 279 impl_writeable_tlv_based!(HolderHTLCOutput, {
 280         (0, amount, required),
 281         (2, cltv_expiry, required),
 282         (4, preimage, option)
 283 });
 284
 285 /// A struct to describe the channel output on the funding transaction.
 286 ///
 287 /// witnessScript is used as part of the witness redeeming the funding utxo.
 288 #[derive(Clone, PartialEq, Eq)]
 289 pub(crate) struct HolderFundingOutput {
 290         funding_redeemscript: Script,
 291         funding_amount: Option<u64>,
 292         opt_anchors: Option<()>,
 293 }
 294
 295
 296 impl HolderFundingOutput {
 297         pub(crate) fn build(funding_redeemscript: Script, funding_amount: u64, opt_anchors: bool) -> Self {
 298                 HolderFundingOutput {
 299                         funding_redeemscript,
 300                         funding_amount: Some(funding_amount),
 301                         opt_anchors: if opt_anchors { Some(()) } else { None },
 302                 }
 303         }
 304
 305         fn opt_anchors(&self) -> bool {
 306                 self.opt_anchors.is_some()
 307         }
 308 }
 309
 310 impl_writeable_tlv_based!(HolderFundingOutput, {
 311         (0, funding_redeemscript, required),
 312         (1, opt_anchors, option),
 313         (3, funding_amount, option),
 314 });
 315
 316 /// A wrapper encapsulating all in-protocol differing outputs types.
 317 ///
 318 /// The generic API offers access to an outputs common attributes or allow transformation such as
 319 /// finalizing an input claiming the output.
 320 #[derive(Clone, PartialEq, Eq)]
 321 pub(crate) enum PackageSolvingData {
 322         RevokedOutput(RevokedOutput),
 323         RevokedHTLCOutput(RevokedHTLCOutput),
 324         CounterpartyOfferedHTLCOutput(CounterpartyOfferedHTLCOutput),
 325         CounterpartyReceivedHTLCOutput(CounterpartyReceivedHTLCOutput),
 326         HolderHTLCOutput(HolderHTLCOutput),
 327         HolderFundingOutput(HolderFundingOutput),
 328 }
 329
 330 impl PackageSolvingData {
 331         fn amount(&self) -> u64 {
 332                 let amt = match self {
 333                         PackageSolvingData::RevokedOutput(ref outp) => outp.amount,
 334                         PackageSolvingData::RevokedHTLCOutput(ref outp) => outp.amount,
 335                         PackageSolvingData::CounterpartyOfferedHTLCOutput(ref outp) => outp.htlc.amount_msat / 1000,
 336                         PackageSolvingData::CounterpartyReceivedHTLCOutput(ref outp) => outp.htlc.amount_msat / 1000,
 337                         // Note: Currently, amounts of holder outputs spending witnesses aren't used
 338                         // as we can't malleate spending package to increase their feerate. This
 339                         // should change with the remaining anchor output patchset.
 340                         PackageSolvingData::HolderHTLCOutput(..) => unreachable!(),
 341                         PackageSolvingData::HolderFundingOutput(ref outp) => {
 342                                 debug_assert!(outp.opt_anchors());
 343                                 outp.funding_amount.unwrap()
 344                         }
 345                 };
 346                 amt
 347         }
 348         fn weight(&self) -> usize {
 349                 let weight = match self {
 350                         PackageSolvingData::RevokedOutput(ref outp) => { outp.weight as usize },
 351                         PackageSolvingData::RevokedHTLCOutput(ref outp) => { outp.weight as usize },
 352                         PackageSolvingData::CounterpartyOfferedHTLCOutput(ref outp) => { weight_offered_htlc(outp.opt_anchors()) as usize },
 353                         PackageSolvingData::CounterpartyReceivedHTLCOutput(ref outp) => { weight_received_htlc(outp.opt_anchors()) as usize },
 354                         // Note: Currently, weights of holder outputs spending witnesses aren't used
 355                         // as we can't malleate spending package to increase their feerate. This
 356                         // should change with the remaining anchor output patchset.
 357                         PackageSolvingData::HolderHTLCOutput(..) => { unreachable!() },
 358                         PackageSolvingData::HolderFundingOutput(..) => { unreachable!() },
 359                 };
 360                 weight
 361         }
 362         fn is_compatible(&self, input: &PackageSolvingData) -> bool {
 363                 match self {
 364                         PackageSolvingData::RevokedOutput(..) => {
 365                                 match input {
 366                                         PackageSolvingData::RevokedHTLCOutput(..) => { true },
 367                                         PackageSolvingData::RevokedOutput(..) => { true },
 368                                         _ => { false }
 369                                 }
 370                         },
 371                         PackageSolvingData::RevokedHTLCOutput(..) => {
 372                                 match input {
 373                                         PackageSolvingData::RevokedOutput(..) => { true },
 374                                         PackageSolvingData::RevokedHTLCOutput(..) => { true },
 375                                         _ => { false }
 376                                 }
 377                         },
 378                         _ => { mem::discriminant(self) == mem::discriminant(&input) }
 379                 }
 380         }
 381         fn finalize_input<Signer: Sign>(&self, bumped_tx: &mut Transaction, i: usize, onchain_handler: &mut OnchainTxHandler<Signer>) -> bool {
 382                 match self {
 383                         PackageSolvingData::RevokedOutput(ref outp) => {
 384                                 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);
 385                                 let witness_script = chan_utils::get_revokeable_redeemscript(&chan_keys.revocation_key, outp.on_counterparty_tx_csv, &chan_keys.broadcaster_delayed_payment_key);
 386                                 //TODO: should we panic on signer failure ?
 387                                 if let Ok(sig) = onchain_handler.signer.sign_justice_revoked_output(&bumped_tx, i, outp.amount, &outp.per_commitment_key, &onchain_handler.secp_ctx) {
 388                                         let mut ser_sig = sig.serialize_der().to_vec();
 389                                         ser_sig.push(EcdsaSighashType::All as u8);
 390                                         bumped_tx.input[i].witness.push(ser_sig);
 391                                         bumped_tx.input[i].witness.push(vec!(1));
 392                                         bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
 393                                 } else { return false; }
 394                         },
 395                         PackageSolvingData::RevokedHTLCOutput(ref outp) => {
 396                                 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);
 397                                 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);
 398                                 //TODO: should we panic on signer failure ?
 399                                 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) {
 400                                         let mut ser_sig = sig.serialize_der().to_vec();
 401                                         ser_sig.push(EcdsaSighashType::All as u8);
 402                                         bumped_tx.input[i].witness.push(ser_sig);
 403                                         bumped_tx.input[i].witness.push(chan_keys.revocation_key.clone().serialize().to_vec());
 404                                         bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
 405                                 } else { return false; }
 406                         },
 407                         PackageSolvingData::CounterpartyOfferedHTLCOutput(ref outp) => {
 408                                 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);
 409                                 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);
 410
 411                                 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) {
 412                                         let mut ser_sig = sig.serialize_der().to_vec();
 413                                         ser_sig.push(EcdsaSighashType::All as u8);
 414                                         bumped_tx.input[i].witness.push(ser_sig);
 415                                         bumped_tx.input[i].witness.push(outp.preimage.0.to_vec());
 416                                         bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
 417                                 }
 418                         },
 419                         PackageSolvingData::CounterpartyReceivedHTLCOutput(ref outp) => {
 420                                 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);
 421                                 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);
 422
 423                                 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
 424                                 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) {
 425                                         let mut ser_sig = sig.serialize_der().to_vec();
 426                                         ser_sig.push(EcdsaSighashType::All as u8);
 427                                         bumped_tx.input[i].witness.push(ser_sig);
 428                                         // Due to BIP146 (MINIMALIF) this must be a zero-length element to relay.
 429                                         bumped_tx.input[i].witness.push(vec![]);
 430                                         bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
 431                                 }
 432                         },
 433                         _ => { panic!("API Error!"); }
 434                 }
 435                 true
 436         }
 437         fn get_finalized_tx<Signer: Sign>(&self, outpoint: &BitcoinOutPoint, onchain_handler: &mut OnchainTxHandler<Signer>) -> Option<Transaction> {
 438                 match self {
 439                         PackageSolvingData::HolderHTLCOutput(ref outp) => { return onchain_handler.get_fully_signed_htlc_tx(outpoint, &outp.preimage); }
 440                         PackageSolvingData::HolderFundingOutput(ref outp) => { return Some(onchain_handler.get_fully_signed_holder_tx(&outp.funding_redeemscript)); }
 441                         _ => { panic!("API Error!"); }
 442                 }
 443         }
 444         fn absolute_tx_timelock(&self, output_conf_height: u32) -> u32 {
 445                 // Get the absolute timelock at which this output can be spent given the height at which
 446                 // this output was confirmed. We use `output_conf_height + 1` as a safe default as we can
 447                 // be confirmed in the next block and transactions with time lock `current_height + 1`
 448                 // always propagate.
 449                 let absolute_timelock = match self {
 450                         PackageSolvingData::RevokedOutput(_) => output_conf_height + 1,
 451                         PackageSolvingData::RevokedHTLCOutput(_) => output_conf_height + 1,
 452                         PackageSolvingData::CounterpartyOfferedHTLCOutput(_) => output_conf_height + 1,
 453                         PackageSolvingData::CounterpartyReceivedHTLCOutput(ref outp) => cmp::max(outp.htlc.cltv_expiry, output_conf_height + 1),
 454                         PackageSolvingData::HolderHTLCOutput(ref outp) => cmp::max(outp.cltv_expiry, output_conf_height + 1),
 455                         PackageSolvingData::HolderFundingOutput(_) => output_conf_height + 1,
 456                 };
 457                 absolute_timelock
 458         }
 459 }
 460
 461 impl_writeable_tlv_based_enum!(PackageSolvingData, ;
 462         (0, RevokedOutput),
 463         (1, RevokedHTLCOutput),
 464         (2, CounterpartyOfferedHTLCOutput),
 465         (3, CounterpartyReceivedHTLCOutput),
 466         (4, HolderHTLCOutput),
 467         (5, HolderFundingOutput),
 468 );
 469
 470 /// A malleable package might be aggregated with other packages to save on fees.
 471 /// A untractable package has been counter-signed and aggregable will break cached counterparty
 472 /// signatures.
 473 #[derive(Clone, PartialEq, Eq)]
 474 pub(crate) enum PackageMalleability {
 475         Malleable,
 476         Untractable,
 477 }
 478
 479 /// A structure to describe a package content that is generated by ChannelMonitor and
 480 /// used by OnchainTxHandler to generate and broadcast transactions settling onchain claims.
 481 ///
 482 /// A package is defined as one or more transactions claiming onchain outputs in reaction
 483 /// to confirmation of a channel transaction. Those packages might be aggregated to save on
 484 /// fees, if satisfaction of outputs's witnessScript let's us do so.
 485 ///
 486 /// As packages are time-sensitive, we fee-bump and rebroadcast them at scheduled intervals.
 487 /// Failing to confirm a package translate as a loss of funds for the user.
 488 #[derive(Clone, PartialEq, Eq)]
 489 pub struct PackageTemplate {
 490         // List of onchain outputs and solving data to generate satisfying witnesses.
 491         inputs: Vec<(BitcoinOutPoint, PackageSolvingData)>,
 492         // Packages are deemed as malleable if we have local knwoledge of at least one set of
 493         // private keys yielding a satisfying witnesses. Malleability implies that we can aggregate
 494         // packages among them to save on fees or rely on RBF to bump their feerates.
 495         // Untractable packages have been counter-signed and thus imply that we can't aggregate
 496         // them without breaking signatures. Fee-bumping strategy will also rely on CPFP.
 497         malleability: PackageMalleability,
 498         // Block height after which the earlier-output belonging to this package is mature for a
 499         // competing claim by the counterparty. As our chain tip becomes nearer from the timelock,
 500         // the fee-bumping frequency will increase. See `OnchainTxHandler::get_height_timer`.
 501         soonest_conf_deadline: u32,
 502         // Determines if this package can be aggregated.
 503         // Timelocked outputs belonging to the same transaction might have differing
 504         // satisfying heights. Picking up the later height among the output set would be a valid
 505         // aggregable strategy but it comes with at least 2 trade-offs :
 506         // * earlier-output fund are going to take longer to come back
 507         // * CLTV delta backing up a corresponding HTLC on an upstream channel could be swallowed
 508         // by the requirement of the later-output part of the set
 509         // For now, we mark such timelocked outputs as non-aggregable, though we might introduce
 510         // smarter aggregable strategy in the future.
 511         aggregable: bool,
 512         // Cache of package feerate committed at previous (re)broadcast. If bumping resources
 513         // (either claimed output value or external utxo), it will keep increasing until holder
 514         // or counterparty successful claim.
 515         feerate_previous: u64,
 516         // Cache of next height at which fee-bumping and rebroadcast will be attempted. In
 517         // the future, we might abstract it to an observed mempool fluctuation.
 518         height_timer: Option<u32>,
 519         // Confirmation height of the claimed outputs set transaction. In case of reorg reaching
 520         // it, we wipe out and forget the package.
 521         height_original: u32,
 522 }
 523
 524 impl PackageTemplate {
 525         pub(crate) fn is_malleable(&self) -> bool {
 526                 self.malleability == PackageMalleability::Malleable
 527         }
 528         pub(crate) fn timelock(&self) -> u32 {
 529                 self.soonest_conf_deadline
 530         }
 531         pub(crate) fn aggregable(&self) -> bool {
 532                 self.aggregable
 533         }
 534         pub(crate) fn set_feerate(&mut self, new_feerate: u64) {
 535                 self.feerate_previous = new_feerate;
 536         }
 537         pub(crate) fn timer(&self) -> Option<u32> {
 538                 if let Some(ref timer) = self.height_timer {
 539                         return Some(*timer);
 540                 }
 541                 None
 542         }
 543         pub(crate) fn set_timer(&mut self, new_timer: Option<u32>) {
 544                 self.height_timer = new_timer;
 545         }
 546         pub(crate) fn outpoints(&self) -> Vec<&BitcoinOutPoint> {
 547                 self.inputs.iter().map(|(o, _)| o).collect()
 548         }
 549         pub(crate) fn inputs(&self) -> impl ExactSizeIterator<Item = &PackageSolvingData> {
 550                 self.inputs.iter().map(|(_, i)| i)
 551         }
 552         pub(crate) fn split_package(&mut self, split_outp: &BitcoinOutPoint) -> Option<PackageTemplate> {
 553                 match self.malleability {
 554                         PackageMalleability::Malleable => {
 555                                 let mut split_package = None;
 556                                 let timelock = self.soonest_conf_deadline;
 557                                 let aggregable = self.aggregable;
 558                                 let feerate_previous = self.feerate_previous;
 559                                 let height_timer = self.height_timer;
 560                                 let height_original = self.height_original;
 561                                 self.inputs.retain(|outp| {
 562                                         if *split_outp == outp.0 {
 563                                                 split_package = Some(PackageTemplate {
 564                                                         inputs: vec![(outp.0, outp.1.clone())],
 565                                                         malleability: PackageMalleability::Malleable,
 566                                                         soonest_conf_deadline: timelock,
 567                                                         aggregable,
 568                                                         feerate_previous,
 569                                                         height_timer,
 570                                                         height_original,
 571                                                 });
 572                                                 return false;
 573                                         }
 574                                         return true;
 575                                 });
 576                                 return split_package;
 577                         },
 578                         _ => {
 579                                 // Note, we may try to split on remote transaction for
 580                                 // which we don't have a competing one (HTLC-Success before
 581                                 // timelock expiration). This explain we don't panic!
 582                                 // We should refactor OnchainTxHandler::block_connected to
 583                                 // only test equality on competing claims.
 584                                 return None;
 585                         }
 586                 }
 587         }
 588         pub(crate) fn merge_package(&mut self, mut merge_from: PackageTemplate) {
 589                 assert_eq!(self.height_original, merge_from.height_original);
 590                 if self.malleability == PackageMalleability::Untractable || merge_from.malleability == PackageMalleability::Untractable {
 591                         panic!("Merging template on untractable packages");
 592                 }
 593                 if !self.aggregable || !merge_from.aggregable {
 594                         panic!("Merging non aggregatable packages");
 595                 }
 596                 if let Some((_, lead_input)) = self.inputs.first() {
 597                         for (_, v) in merge_from.inputs.iter() {
 598                                 if !lead_input.is_compatible(v) { panic!("Merging outputs from differing types !"); }
 599                         }
 600                 } else { panic!("Merging template on an empty package"); }
 601                 for (k, v) in merge_from.inputs.drain(..) {
 602                         self.inputs.push((k, v));
 603                 }
 604                 //TODO: verify coverage and sanity?
 605                 if self.soonest_conf_deadline > merge_from.soonest_conf_deadline {
 606                         self.soonest_conf_deadline = merge_from.soonest_conf_deadline;
 607                 }
 608                 if self.feerate_previous > merge_from.feerate_previous {
 609                         self.feerate_previous = merge_from.feerate_previous;
 610                 }
 611                 self.height_timer = cmp::min(self.height_timer, merge_from.height_timer);
 612         }
 613         /// Gets the amount of all outptus being spent by this package, only valid for malleable
 614         /// packages.
 615         pub(crate) fn package_amount(&self) -> u64 {
 616                 let mut amounts = 0;
 617                 for (_, outp) in self.inputs.iter() {
 618                         amounts += outp.amount();
 619                 }
 620                 amounts
 621         }
 622         pub(crate) fn package_timelock(&self) -> u32 {
 623                 self.inputs.iter().map(|(_, outp)| outp.absolute_tx_timelock(self.height_original))
 624                         .max().expect("There must always be at least one output to spend in a PackageTemplate")
 625         }
 626         pub(crate) fn package_weight(&self, destination_script: &Script) -> usize {
 627                 let mut inputs_weight = 0;
 628                 let mut witnesses_weight = 2; // count segwit flags
 629                 for (_, outp) in self.inputs.iter() {
 630                         // previous_out_point: 36 bytes ; var_int: 1 byte ; sequence: 4 bytes
 631                         inputs_weight += 41 * WITNESS_SCALE_FACTOR;
 632                         witnesses_weight += outp.weight();
 633                 }
 634                 // version: 4 bytes ; count_tx_in: 1 byte ; count_tx_out: 1 byte ; lock_time: 4 bytes
 635                 let transaction_weight = 10 * WITNESS_SCALE_FACTOR;
 636                 // value: 8 bytes ; var_int: 1 byte ; pk_script: `destination_script.len()`
 637                 let output_weight = (8 + 1 + destination_script.len()) * WITNESS_SCALE_FACTOR;
 638                 inputs_weight + witnesses_weight + transaction_weight + output_weight
 639         }
 640         pub(crate) fn finalize_malleable_package<L: Deref, Signer: Sign>(
 641                 &self, onchain_handler: &mut OnchainTxHandler<Signer>, value: u64, destination_script: Script, logger: &L
 642         ) -> Option<Transaction> where L::Target: Logger {
 643                 debug_assert!(self.is_malleable());
 644                 let mut bumped_tx = Transaction {
 645                         version: 2,
 646                         lock_time: PackedLockTime::ZERO,
 647                         input: vec![],
 648                         output: vec![TxOut {
 649                                 script_pubkey: destination_script,
 650                                 value,
 651                         }],
 652                 };
 653                 for (outpoint, _) in self.inputs.iter() {
 654                         bumped_tx.input.push(TxIn {
 655                                 previous_output: *outpoint,
 656                                 script_sig: Script::new(),
 657                                 sequence: Sequence::ENABLE_RBF_NO_LOCKTIME,
 658                                 witness: Witness::new(),
 659                         });
 660                 }
 661                 for (i, (outpoint, out)) in self.inputs.iter().enumerate() {
 662                         log_debug!(logger, "Adding claiming input for outpoint {}:{}", outpoint.txid, outpoint.vout);
 663                         if !out.finalize_input(&mut bumped_tx, i, onchain_handler) { return None; }
 664                 }
 665                 log_debug!(logger, "Finalized transaction {} ready to broadcast", bumped_tx.txid());
 666                 Some(bumped_tx)
 667         }
 668         pub(crate) fn finalize_untractable_package<L: Deref, Signer: Sign>(
 669                 &self, onchain_handler: &mut OnchainTxHandler<Signer>, logger: &L,
 670         ) -> Option<Transaction> where L::Target: Logger {
 671                 debug_assert!(!self.is_malleable());
 672                 if let Some((outpoint, outp)) = self.inputs.first() {
 673                         if let Some(final_tx) = outp.get_finalized_tx(outpoint, onchain_handler) {
 674                                 log_debug!(logger, "Adding claiming input for outpoint {}:{}", outpoint.txid, outpoint.vout);
 675                                 log_debug!(logger, "Finalized transaction {} ready to broadcast", final_tx.txid());
 676                                 return Some(final_tx);
 677                         }
 678                         return None;
 679                 } else { panic!("API Error: Package must not be inputs empty"); }
 680         }
 681         /// In LN, output claimed are time-sensitive, which means we have to spend them before reaching some timelock expiration. At in-channel
 682         /// 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
 683         /// height that once reached we should generate a new bumped "version" of the claim tx to be sure that we safely claim outputs before
 684         /// that our counterparty can do so. If timelock expires soon, height timer is going to be scaled down in consequence to increase
 685         /// frequency of the bump and so increase our bets of success.
 686         pub(crate) fn get_height_timer(&self, current_height: u32) -> u32 {
 687                 if self.soonest_conf_deadline <= current_height + MIDDLE_FREQUENCY_BUMP_INTERVAL {
 688                         return current_height + HIGH_FREQUENCY_BUMP_INTERVAL
 689                 } else if self.soonest_conf_deadline - current_height <= LOW_FREQUENCY_BUMP_INTERVAL {
 690                         return current_height + MIDDLE_FREQUENCY_BUMP_INTERVAL
 691                 }
 692                 current_height + LOW_FREQUENCY_BUMP_INTERVAL
 693         }
 694
 695         /// Returns value in satoshis to be included as package outgoing output amount and feerate
 696         /// which was used to generate the value. Will not return less than `dust_limit_sats` for the
 697         /// value.
 698         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)>
 699                 where F::Target: FeeEstimator,
 700                       L::Target: Logger,
 701         {
 702                 debug_assert!(self.malleability == PackageMalleability::Malleable, "The package output is fixed for non-malleable packages");
 703                 let input_amounts = self.package_amount();
 704                 assert!(dust_limit_sats as i64 > 0, "Output script must be broadcastable/have a 'real' dust limit.");
 705                 // If old feerate is 0, first iteration of this claim, use normal fee calculation
 706                 if self.feerate_previous != 0 {
 707                         if let Some((new_fee, feerate)) = feerate_bump(predicted_weight, input_amounts, self.feerate_previous, fee_estimator, logger) {
 708                                 return Some((cmp::max(input_amounts as i64 - new_fee as i64, dust_limit_sats as i64) as u64, feerate));
 709                         }
 710                 } else {
 711                         if let Some((new_fee, feerate)) = compute_fee_from_spent_amounts(input_amounts, predicted_weight, fee_estimator, logger) {
 712                                 return Some((cmp::max(input_amounts as i64 - new_fee as i64, dust_limit_sats as i64) as u64, feerate));
 713                         }
 714                 }
 715                 None
 716         }
 717
 718         #[cfg(anchors)]
 719         /// Computes a feerate based on the given confirmation target. If a previous feerate was used,
 720         /// and the new feerate is below it, we'll use a 25% increase of the previous feerate instead of
 721         /// the new one.
 722         pub(crate) fn compute_package_feerate<F: Deref>(
 723                 &self, fee_estimator: &LowerBoundedFeeEstimator<F>, conf_target: ConfirmationTarget,
 724         ) -> u32 where F::Target: FeeEstimator {
 725                 let feerate_estimate = fee_estimator.bounded_sat_per_1000_weight(conf_target);
 726                 if self.feerate_previous != 0 {
 727                         // If old feerate inferior to actual one given back by Fee Estimator, use it to compute new fee...
 728                         if feerate_estimate as u64 > self.feerate_previous {
 729                                 feerate_estimate
 730                         } else {
 731                                 // ...else just increase the previous feerate by 25% (because that's a nice number)
 732                                 (self.feerate_previous + (self.feerate_previous / 4)).try_into().unwrap_or(u32::max_value())
 733                         }
 734                 } else {
 735                         feerate_estimate
 736                 }
 737         }
 738
 739         /// Determines whether a package contains an input which must have additional external inputs
 740         /// attached to help the spending transaction reach confirmation.
 741         pub(crate) fn requires_external_funding(&self) -> bool {
 742                 self.inputs.iter().find(|input| match input.1 {
 743                         PackageSolvingData::HolderFundingOutput(ref outp) => outp.opt_anchors(),
 744                         _ => false,
 745                 }).is_some()
 746         }
 747
 748         pub (crate) fn build_package(txid: Txid, vout: u32, input_solving_data: PackageSolvingData, soonest_conf_deadline: u32, aggregable: bool, height_original: u32) -> Self {
 749                 let malleability = match input_solving_data {
 750                         PackageSolvingData::RevokedOutput(..) => PackageMalleability::Malleable,
 751                         PackageSolvingData::RevokedHTLCOutput(..) => PackageMalleability::Malleable,
 752                         PackageSolvingData::CounterpartyOfferedHTLCOutput(..) => PackageMalleability::Malleable,
 753                         PackageSolvingData::CounterpartyReceivedHTLCOutput(..) => PackageMalleability::Malleable,
 754                         PackageSolvingData::HolderHTLCOutput(..) => PackageMalleability::Untractable,
 755                         PackageSolvingData::HolderFundingOutput(..) => PackageMalleability::Untractable,
 756                 };
 757                 let mut inputs = Vec::with_capacity(1);
 758                 inputs.push((BitcoinOutPoint { txid, vout }, input_solving_data));
 759                 PackageTemplate {
 760                         inputs,
 761                         malleability,
 762                         soonest_conf_deadline,
 763                         aggregable,
 764                         feerate_previous: 0,
 765                         height_timer: None,
 766                         height_original,
 767                 }
 768         }
 769 }
 770
 771 impl Writeable for PackageTemplate {
 772         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 773                 writer.write_all(&byte_utils::be64_to_array(self.inputs.len() as u64))?;
 774                 for (ref outpoint, ref rev_outp) in self.inputs.iter() {
 775                         outpoint.write(writer)?;
 776                         rev_outp.write(writer)?;
 777                 }
 778                 write_tlv_fields!(writer, {
 779                         (0, self.soonest_conf_deadline, required),
 780                         (2, self.feerate_previous, required),
 781                         (4, self.height_original, required),
 782                         (6, self.height_timer, option)
 783                 });
 784                 Ok(())
 785         }
 786 }
 787
 788 impl Readable for PackageTemplate {
 789         fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
 790                 let inputs_count = <u64 as Readable>::read(reader)?;
 791                 let mut inputs: Vec<(BitcoinOutPoint, PackageSolvingData)> = Vec::with_capacity(cmp::min(inputs_count as usize, MAX_ALLOC_SIZE / 128));
 792                 for _ in 0..inputs_count {
 793                         let outpoint = Readable::read(reader)?;
 794                         let rev_outp = Readable::read(reader)?;
 795                         inputs.push((outpoint, rev_outp));
 796                 }
 797                 let (malleability, aggregable) = if let Some((_, lead_input)) = inputs.first() {
 798                         match lead_input {
 799                                 PackageSolvingData::RevokedOutput(..) => { (PackageMalleability::Malleable, true) },
 800                                 PackageSolvingData::RevokedHTLCOutput(..) => { (PackageMalleability::Malleable, true) },
 801                                 PackageSolvingData::CounterpartyOfferedHTLCOutput(..) => { (PackageMalleability::Malleable, true) },
 802                                 PackageSolvingData::CounterpartyReceivedHTLCOutput(..) => { (PackageMalleability::Malleable, false) },
 803                                 PackageSolvingData::HolderHTLCOutput(..) => { (PackageMalleability::Untractable, false) },
 804                                 PackageSolvingData::HolderFundingOutput(..) => { (PackageMalleability::Untractable, false) },
 805                         }
 806                 } else { return Err(DecodeError::InvalidValue); };
 807                 let mut soonest_conf_deadline = 0;
 808                 let mut feerate_previous = 0;
 809                 let mut height_timer = None;
 810                 let mut height_original = 0;
 811                 read_tlv_fields!(reader, {
 812                         (0, soonest_conf_deadline, required),
 813                         (2, feerate_previous, required),
 814                         (4, height_original, required),
 815                         (6, height_timer, option),
 816                 });
 817                 Ok(PackageTemplate {
 818                         inputs,
 819                         malleability,
 820                         soonest_conf_deadline,
 821                         aggregable,
 822                         feerate_previous,
 823                         height_timer,
 824                         height_original,
 825                 })
 826         }
 827 }
 828
 829 /// Attempt to propose a bumping fee for a transaction from its spent output's values and predicted
 830 /// weight. We start with the highest priority feerate returned by the node's fee estimator then
 831 /// fall-back to lower priorities until we have enough value available to suck from.
 832 ///
 833 /// If the proposed fee is less than the available spent output's values, we return the proposed
 834 /// fee and the corresponding updated feerate. If the proposed fee is equal or more than the
 835 /// available spent output's values, we return nothing
 836 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)>
 837         where F::Target: FeeEstimator,
 838               L::Target: Logger,
 839 {
 840         let mut updated_feerate = fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::HighPriority) as u64;
 841         let mut fee = updated_feerate * (predicted_weight as u64) / 1000;
 842         if input_amounts <= fee {
 843                 updated_feerate = fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Normal) as u64;
 844                 fee = updated_feerate * (predicted_weight as u64) / 1000;
 845                 if input_amounts <= fee {
 846                         updated_feerate = fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Background) as u64;
 847                         fee = updated_feerate * (predicted_weight as u64) / 1000;
 848                         if input_amounts <= fee {
 849                                 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)",
 850                                         fee, input_amounts);
 851                                 None
 852                         } else {
 853                                 log_warn!(logger, "Used low priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
 854                                         input_amounts);
 855                                 Some((fee, updated_feerate))
 856                         }
 857                 } else {
 858                         log_warn!(logger, "Used medium priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
 859                                 input_amounts);
 860                         Some((fee, updated_feerate))
 861                 }
 862         } else {
 863                 Some((fee, updated_feerate))
 864         }
 865 }
 866
 867 /// Attempt to propose a bumping fee for a transaction from its spent output's values and predicted
 868 /// weight. If feerates proposed by the fee-estimator have been increasing since last fee-bumping
 869 /// attempt, use them. Otherwise, blindly bump the feerate by 25% of the previous feerate. We also
 870 /// verify that those bumping heuristics respect BIP125 rules 3) and 4) and if required adjust
 871 /// the new fee to meet the RBF policy requirement.
 872 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)>
 873         where F::Target: FeeEstimator,
 874               L::Target: Logger,
 875 {
 876         // If old feerate inferior to actual one given back by Fee Estimator, use it to compute new fee...
 877         let new_fee = if let Some((new_fee, _)) = compute_fee_from_spent_amounts(input_amounts, predicted_weight, fee_estimator, logger) {
 878                 let updated_feerate = new_fee / (predicted_weight as u64 * 1000);
 879                 if updated_feerate > previous_feerate {
 880                         new_fee
 881                 } else {
 882                         // ...else just increase the previous feerate by 25% (because that's a nice number)
 883                         let new_fee = previous_feerate * (predicted_weight as u64) / 750;
 884                         if input_amounts <= new_fee {
 885                                 log_warn!(logger, "Can't 25% bump new claiming tx, amount {} is too small", input_amounts);
 886                                 return None;
 887                         }
 888                         new_fee
 889                 }
 890         } else {
 891                 log_warn!(logger, "Can't new-estimation bump new claiming tx, amount {} is too small", input_amounts);
 892                 return None;
 893         };
 894
 895         let previous_fee = previous_feerate * (predicted_weight as u64) / 1000;
 896         let min_relay_fee = MIN_RELAY_FEE_SAT_PER_1000_WEIGHT * (predicted_weight as u64) / 1000;
 897         // BIP 125 Opt-in Full Replace-by-Fee Signaling
 898         //      * 3. The replacement transaction pays an absolute fee of at least the sum paid by the original transactions.
 899         //      * 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.
 900         let new_fee = if new_fee < previous_fee + min_relay_fee {
 901                 new_fee + previous_fee + min_relay_fee - new_fee
 902         } else {
 903                 new_fee
 904         };
 905         Some((new_fee, new_fee * 1000 / (predicted_weight as u64)))
 906 }
 907
 908 #[cfg(test)]
 909 mod tests {
 910         use crate::chain::package::{CounterpartyOfferedHTLCOutput, CounterpartyReceivedHTLCOutput, HolderHTLCOutput, PackageTemplate, PackageSolvingData, RevokedOutput, WEIGHT_REVOKED_OUTPUT, weight_offered_htlc, weight_received_htlc};
 911         use crate::chain::Txid;
 912         use crate::ln::chan_utils::HTLCOutputInCommitment;
 913         use crate::ln::{PaymentPreimage, PaymentHash};
 914
 915         use bitcoin::blockdata::constants::WITNESS_SCALE_FACTOR;
 916         use bitcoin::blockdata::script::Script;
 917         use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
 918
 919         use bitcoin::hashes::hex::FromHex;
 920
 921         use bitcoin::secp256k1::{PublicKey,SecretKey};
 922         use bitcoin::secp256k1::Secp256k1;
 923
 924         macro_rules! dumb_revk_output {
 925                 ($secp_ctx: expr) => {
 926                         {
 927                                 let dumb_scalar = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
 928                                 let dumb_point = PublicKey::from_secret_key(&$secp_ctx, &dumb_scalar);
 929                                 PackageSolvingData::RevokedOutput(RevokedOutput::build(dumb_point, dumb_point, dumb_point, dumb_scalar, 0, 0))
 930                         }
 931                 }
 932         }
 933
 934         macro_rules! dumb_counterparty_output {
 935                 ($secp_ctx: expr, $amt: expr, $opt_anchors: expr) => {
 936                         {
 937                                 let dumb_scalar = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
 938                                 let dumb_point = PublicKey::from_secret_key(&$secp_ctx, &dumb_scalar);
 939                                 let hash = PaymentHash([1; 32]);
 940                                 let htlc = HTLCOutputInCommitment { offered: true, amount_msat: $amt, cltv_expiry: 0, payment_hash: hash, transaction_output_index: None };
 941                                 PackageSolvingData::CounterpartyReceivedHTLCOutput(CounterpartyReceivedHTLCOutput::build(dumb_point, dumb_point, dumb_point, htlc, $opt_anchors))
 942                         }
 943                 }
 944         }
 945
 946         macro_rules! dumb_counterparty_offered_output {
 947                 ($secp_ctx: expr, $amt: expr, $opt_anchors: expr) => {
 948                         {
 949                                 let dumb_scalar = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
 950                                 let dumb_point = PublicKey::from_secret_key(&$secp_ctx, &dumb_scalar);
 951                                 let hash = PaymentHash([1; 32]);
 952                                 let preimage = PaymentPreimage([2;32]);
 953                                 let htlc = HTLCOutputInCommitment { offered: false, amount_msat: $amt, cltv_expiry: 1000, payment_hash: hash, transaction_output_index: None };
 954                                 PackageSolvingData::CounterpartyOfferedHTLCOutput(CounterpartyOfferedHTLCOutput::build(dumb_point, dumb_point, dumb_point, preimage, htlc, $opt_anchors))
 955                         }
 956                 }
 957         }
 958
 959         macro_rules! dumb_htlc_output {
 960                 () => {
 961                         {
 962                                 let preimage = PaymentPreimage([2;32]);
 963                                 PackageSolvingData::HolderHTLCOutput(HolderHTLCOutput::build_accepted(preimage, 0))
 964                         }
 965                 }
 966         }
 967
 968         #[test]
 969         #[should_panic]
 970         fn test_package_differing_heights() {
 971                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
 972                 let secp_ctx = Secp256k1::new();
 973                 let revk_outp = dumb_revk_output!(secp_ctx);
 974
 975                 let mut package_one_hundred = PackageTemplate::build_package(txid, 0, revk_outp.clone(), 1000, true, 100);
 976                 let package_two_hundred = PackageTemplate::build_package(txid, 1, revk_outp.clone(), 1000, true, 200);
 977                 package_one_hundred.merge_package(package_two_hundred);
 978         }
 979
 980         #[test]
 981         #[should_panic]
 982         fn test_package_untractable_merge_to() {
 983                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
 984                 let secp_ctx = Secp256k1::new();
 985                 let revk_outp = dumb_revk_output!(secp_ctx);
 986                 let htlc_outp = dumb_htlc_output!();
 987
 988                 let mut untractable_package = PackageTemplate::build_package(txid, 0, revk_outp.clone(), 1000, true, 100);
 989                 let malleable_package = PackageTemplate::build_package(txid, 1, htlc_outp.clone(), 1000, true, 100);
 990                 untractable_package.merge_package(malleable_package);
 991         }
 992
 993         #[test]
 994         #[should_panic]
 995         fn test_package_untractable_merge_from() {
 996                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
 997                 let secp_ctx = Secp256k1::new();
 998                 let htlc_outp = dumb_htlc_output!();
 999                 let revk_outp = dumb_revk_output!(secp_ctx);
1000
1001                 let mut malleable_package = PackageTemplate::build_package(txid, 0, htlc_outp.clone(), 1000, true, 100);
1002                 let untractable_package = PackageTemplate::build_package(txid, 1, revk_outp.clone(), 1000, true, 100);
1003                 malleable_package.merge_package(untractable_package);
1004         }
1005
1006         #[test]
1007         #[should_panic]
1008         fn test_package_noaggregation_to() {
1009                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1010                 let secp_ctx = Secp256k1::new();
1011                 let revk_outp = dumb_revk_output!(secp_ctx);
1012
1013                 let mut noaggregation_package = PackageTemplate::build_package(txid, 0, revk_outp.clone(), 1000, false, 100);
1014                 let aggregation_package = PackageTemplate::build_package(txid, 1, revk_outp.clone(), 1000, true, 100);
1015                 noaggregation_package.merge_package(aggregation_package);
1016         }
1017
1018         #[test]
1019         #[should_panic]
1020         fn test_package_noaggregation_from() {
1021                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1022                 let secp_ctx = Secp256k1::new();
1023                 let revk_outp = dumb_revk_output!(secp_ctx);
1024
1025                 let mut aggregation_package = PackageTemplate::build_package(txid, 0, revk_outp.clone(), 1000, true, 100);
1026                 let noaggregation_package = PackageTemplate::build_package(txid, 1, revk_outp.clone(), 1000, false, 100);
1027                 aggregation_package.merge_package(noaggregation_package);
1028         }
1029
1030         #[test]
1031         #[should_panic]
1032         fn test_package_empty() {
1033                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1034                 let secp_ctx = Secp256k1::new();
1035                 let revk_outp = dumb_revk_output!(secp_ctx);
1036
1037                 let mut empty_package = PackageTemplate::build_package(txid, 0, revk_outp.clone(), 1000, true, 100);
1038                 empty_package.inputs = vec![];
1039                 let package = PackageTemplate::build_package(txid, 1, revk_outp.clone(), 1000, true, 100);
1040                 empty_package.merge_package(package);
1041         }
1042
1043         #[test]
1044         #[should_panic]
1045         fn test_package_differing_categories() {
1046                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1047                 let secp_ctx = Secp256k1::new();
1048                 let revk_outp = dumb_revk_output!(secp_ctx);
1049                 let counterparty_outp = dumb_counterparty_output!(secp_ctx, 0, false);
1050
1051                 let mut revoked_package = PackageTemplate::build_package(txid, 0, revk_outp, 1000, true, 100);
1052                 let counterparty_package = PackageTemplate::build_package(txid, 1, counterparty_outp, 1000, true, 100);
1053                 revoked_package.merge_package(counterparty_package);
1054         }
1055
1056         #[test]
1057         fn test_package_split_malleable() {
1058                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1059                 let secp_ctx = Secp256k1::new();
1060                 let revk_outp_one = dumb_revk_output!(secp_ctx);
1061                 let revk_outp_two = dumb_revk_output!(secp_ctx);
1062                 let revk_outp_three = dumb_revk_output!(secp_ctx);
1063
1064                 let mut package_one = PackageTemplate::build_package(txid, 0, revk_outp_one, 1000, true, 100);
1065                 let package_two = PackageTemplate::build_package(txid, 1, revk_outp_two, 1000, true, 100);
1066                 let package_three = PackageTemplate::build_package(txid, 2, revk_outp_three, 1000, true, 100);
1067
1068                 package_one.merge_package(package_two);
1069                 package_one.merge_package(package_three);
1070                 assert_eq!(package_one.outpoints().len(), 3);
1071
1072                 if let Some(split_package) = package_one.split_package(&BitcoinOutPoint { txid, vout: 1 }) {
1073                         // Packages attributes should be identical
1074                         assert!(split_package.is_malleable());
1075                         assert_eq!(split_package.soonest_conf_deadline, package_one.soonest_conf_deadline);
1076                         assert_eq!(split_package.aggregable, package_one.aggregable);
1077                         assert_eq!(split_package.feerate_previous, package_one.feerate_previous);
1078                         assert_eq!(split_package.height_timer, package_one.height_timer);
1079                         assert_eq!(split_package.height_original, package_one.height_original);
1080                 } else { panic!(); }
1081                 assert_eq!(package_one.outpoints().len(), 2);
1082         }
1083
1084         #[test]
1085         fn test_package_split_untractable() {
1086                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1087                 let htlc_outp_one = dumb_htlc_output!();
1088
1089                 let mut package_one = PackageTemplate::build_package(txid, 0, htlc_outp_one, 1000, true, 100);
1090                 let ret_split = package_one.split_package(&BitcoinOutPoint { txid, vout: 0});
1091                 assert!(ret_split.is_none());
1092         }
1093
1094         #[test]
1095         fn test_package_timer() {
1096                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1097                 let secp_ctx = Secp256k1::new();
1098                 let revk_outp = dumb_revk_output!(secp_ctx);
1099
1100                 let mut package = PackageTemplate::build_package(txid, 0, revk_outp, 1000, true, 100);
1101                 let timer_none = package.timer();
1102                 assert!(timer_none.is_none());
1103                 package.set_timer(Some(100));
1104                 if let Some(timer_some) = package.timer() {
1105                         assert_eq!(timer_some, 100);
1106                 } else { panic!() }
1107         }
1108
1109         #[test]
1110         fn test_package_amounts() {
1111                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1112                 let secp_ctx = Secp256k1::new();
1113                 let counterparty_outp = dumb_counterparty_output!(secp_ctx, 1_000_000, false);
1114
1115                 let package = PackageTemplate::build_package(txid, 0, counterparty_outp, 1000, true, 100);
1116                 assert_eq!(package.package_amount(), 1000);
1117         }
1118
1119         #[test]
1120         fn test_package_weight() {
1121                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1122                 let secp_ctx = Secp256k1::new();
1123
1124                 // (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)
1125                 let weight_sans_output = (4 + 4 + 1 + 36 + 4 + 1 + 1 + 8 + 1) * WITNESS_SCALE_FACTOR + 2;
1126
1127                 {
1128                         let revk_outp = dumb_revk_output!(secp_ctx);
1129                         let package = PackageTemplate::build_package(txid, 0, revk_outp, 0, true, 100);
1130                         assert_eq!(package.package_weight(&Script::new()),  weight_sans_output + WEIGHT_REVOKED_OUTPUT as usize);
1131                 }
1132
1133                 {
1134                         for &opt_anchors in [false, true].iter() {
1135                                 let counterparty_outp = dumb_counterparty_output!(secp_ctx, 1_000_000, opt_anchors);
1136                                 let package = PackageTemplate::build_package(txid, 0, counterparty_outp, 1000, true, 100);
1137                                 assert_eq!(package.package_weight(&Script::new()), weight_sans_output + weight_received_htlc(opt_anchors) as usize);
1138                         }
1139                 }
1140
1141                 {
1142                         for &opt_anchors in [false, true].iter() {
1143                                 let counterparty_outp = dumb_counterparty_offered_output!(secp_ctx, 1_000_000, opt_anchors);
1144                                 let package = PackageTemplate::build_package(txid, 0, counterparty_outp, 1000, true, 100);
1145                                 assert_eq!(package.package_weight(&Script::new()), weight_sans_output + weight_offered_htlc(opt_anchors) as usize);
1146                         }
1147                 }
1148         }
1149 }