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