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