_ 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         opt_anchors: Option<()>,
 290 }
 291
 292
 293 impl HolderFundingOutput {
 294         pub(crate) fn build(funding_redeemscript: Script, opt_anchors: bool) -> Self {
 295                 HolderFundingOutput {
 296                         funding_redeemscript,
 297                         opt_anchors: if opt_anchors { Some(()) } else { None },
 298                 }
 299         }
 300
 301         fn opt_anchors(&self) -> bool {
 302                 self.opt_anchors.is_some()
 303         }
 304 }
 305
 306 impl_writeable_tlv_based!(HolderFundingOutput, {
 307         (0, funding_redeemscript, required),
 308         (1, opt_anchors, option),
 309 });
 310
 311 /// A wrapper encapsulating all in-protocol differing outputs types.
 312 ///
 313 /// The generic API offers access to an outputs common attributes or allow transformation such as
 314 /// finalizing an input claiming the output.
 315 #[derive(Clone, PartialEq, Eq)]
 316 pub(crate) enum PackageSolvingData {
 317         RevokedOutput(RevokedOutput),
 318         RevokedHTLCOutput(RevokedHTLCOutput),
 319         CounterpartyOfferedHTLCOutput(CounterpartyOfferedHTLCOutput),
 320         CounterpartyReceivedHTLCOutput(CounterpartyReceivedHTLCOutput),
 321         HolderHTLCOutput(HolderHTLCOutput),
 322         HolderFundingOutput(HolderFundingOutput),
 323 }
 324
 325 impl PackageSolvingData {
 326         fn amount(&self) -> u64 {
 327                 let amt = match self {
 328                         PackageSolvingData::RevokedOutput(ref outp) => { outp.amount },
 329                         PackageSolvingData::RevokedHTLCOutput(ref outp) => { outp.amount },
 330                         PackageSolvingData::CounterpartyOfferedHTLCOutput(ref outp) => { outp.htlc.amount_msat / 1000 },
 331                         PackageSolvingData::CounterpartyReceivedHTLCOutput(ref outp) => { outp.htlc.amount_msat / 1000 },
 332                         // Note: Currently, amounts of holder outputs spending witnesses aren't used
 333                         // as we can't malleate spending package to increase their feerate. This
 334                         // should change with the remaining anchor output patchset.
 335                         PackageSolvingData::HolderHTLCOutput(..) => { unreachable!() },
 336                         PackageSolvingData::HolderFundingOutput(..) => { unreachable!() },
 337                 };
 338                 amt
 339         }
 340         fn weight(&self) -> usize {
 341                 let weight = match self {
 342                         PackageSolvingData::RevokedOutput(ref outp) => { outp.weight as usize },
 343                         PackageSolvingData::RevokedHTLCOutput(ref outp) => { outp.weight as usize },
 344                         PackageSolvingData::CounterpartyOfferedHTLCOutput(ref outp) => { weight_offered_htlc(outp.opt_anchors()) as usize },
 345                         PackageSolvingData::CounterpartyReceivedHTLCOutput(ref outp) => { weight_received_htlc(outp.opt_anchors()) as usize },
 346                         // Note: Currently, weights of holder outputs spending witnesses aren't used
 347                         // as we can't malleate spending package to increase their feerate. This
 348                         // should change with the remaining anchor output patchset.
 349                         PackageSolvingData::HolderHTLCOutput(..) => { unreachable!() },
 350                         PackageSolvingData::HolderFundingOutput(..) => { unreachable!() },
 351                 };
 352                 weight
 353         }
 354         fn is_compatible(&self, input: &PackageSolvingData) -> bool {
 355                 match self {
 356                         PackageSolvingData::RevokedOutput(..) => {
 357                                 match input {
 358                                         PackageSolvingData::RevokedHTLCOutput(..) => { true },
 359                                         PackageSolvingData::RevokedOutput(..) => { true },
 360                                         _ => { false }
 361                                 }
 362                         },
 363                         PackageSolvingData::RevokedHTLCOutput(..) => {
 364                                 match input {
 365                                         PackageSolvingData::RevokedOutput(..) => { true },
 366                                         PackageSolvingData::RevokedHTLCOutput(..) => { true },
 367                                         _ => { false }
 368                                 }
 369                         },
 370                         _ => { mem::discriminant(self) == mem::discriminant(&input) }
 371                 }
 372         }
 373         fn finalize_input<Signer: Sign>(&self, bumped_tx: &mut Transaction, i: usize, onchain_handler: &mut OnchainTxHandler<Signer>) -> bool {
 374                 match self {
 375                         PackageSolvingData::RevokedOutput(ref outp) => {
 376                                 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) {
 377                                         let witness_script = chan_utils::get_revokeable_redeemscript(&chan_keys.revocation_key, outp.on_counterparty_tx_csv, &chan_keys.broadcaster_delayed_payment_key);
 378                                         //TODO: should we panic on signer failure ?
 379                                         if let Ok(sig) = onchain_handler.signer.sign_justice_revoked_output(&bumped_tx, i, outp.amount, &outp.per_commitment_key, &onchain_handler.secp_ctx) {
 380                                                 let mut ser_sig = sig.serialize_der().to_vec();
 381                                                 ser_sig.push(EcdsaSighashType::All as u8);
 382                                                 bumped_tx.input[i].witness.push(ser_sig);
 383                                                 bumped_tx.input[i].witness.push(vec!(1));
 384                                                 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
 385                                         } else { return false; }
 386                                 }
 387                         },
 388                         PackageSolvingData::RevokedHTLCOutput(ref outp) => {
 389                                 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) {
 390                                         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);
 391                                         //TODO: should we panic on signer failure ?
 392                                         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) {
 393                                                 let mut ser_sig = sig.serialize_der().to_vec();
 394                                                 ser_sig.push(EcdsaSighashType::All as u8);
 395                                                 bumped_tx.input[i].witness.push(ser_sig);
 396                                                 bumped_tx.input[i].witness.push(chan_keys.revocation_key.clone().serialize().to_vec());
 397                                                 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
 398                                         } else { return false; }
 399                                 }
 400                         },
 401                         PackageSolvingData::CounterpartyOfferedHTLCOutput(ref outp) => {
 402                                 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) {
 403                                         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);
 404
 405                                         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) {
 406                                                 let mut ser_sig = sig.serialize_der().to_vec();
 407                                                 ser_sig.push(EcdsaSighashType::All as u8);
 408                                                 bumped_tx.input[i].witness.push(ser_sig);
 409                                                 bumped_tx.input[i].witness.push(outp.preimage.0.to_vec());
 410                                                 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
 411                                         }
 412                                 }
 413                         },
 414                         PackageSolvingData::CounterpartyReceivedHTLCOutput(ref outp) => {
 415                                 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) {
 416                                         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);
 417
 418                                         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
 419                                         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) {
 420                                                 let mut ser_sig = sig.serialize_der().to_vec();
 421                                                 ser_sig.push(EcdsaSighashType::All as u8);
 422                                                 bumped_tx.input[i].witness.push(ser_sig);
 423                                                 // Due to BIP146 (MINIMALIF) this must be a zero-length element to relay.
 424                                                 bumped_tx.input[i].witness.push(vec![]);
 425                                                 bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
 426                                         }
 427                                 }
 428                         },
 429                         _ => { panic!("API Error!"); }
 430                 }
 431                 true
 432         }
 433         fn get_finalized_tx<Signer: Sign>(&self, outpoint: &BitcoinOutPoint, onchain_handler: &mut OnchainTxHandler<Signer>) -> Option<Transaction> {
 434                 match self {
 435                         PackageSolvingData::HolderHTLCOutput(ref outp) => { return onchain_handler.get_fully_signed_htlc_tx(outpoint, &outp.preimage); }
 436                         PackageSolvingData::HolderFundingOutput(ref outp) => { return Some(onchain_handler.get_fully_signed_holder_tx(&outp.funding_redeemscript)); }
 437                         _ => { panic!("API Error!"); }
 438                 }
 439         }
 440         fn absolute_tx_timelock(&self, output_conf_height: u32) -> u32 {
 441                 // Get the absolute timelock at which this output can be spent given the height at which
 442                 // this output was confirmed. We use `output_conf_height + 1` as a safe default as we can
 443                 // be confirmed in the next block and transactions with time lock `current_height + 1`
 444                 // always propagate.
 445                 let absolute_timelock = match self {
 446                         PackageSolvingData::RevokedOutput(_) => output_conf_height + 1,
 447                         PackageSolvingData::RevokedHTLCOutput(_) => output_conf_height + 1,
 448                         PackageSolvingData::CounterpartyOfferedHTLCOutput(_) => output_conf_height + 1,
 449                         PackageSolvingData::CounterpartyReceivedHTLCOutput(ref outp) => cmp::max(outp.htlc.cltv_expiry, output_conf_height + 1),
 450                         PackageSolvingData::HolderHTLCOutput(ref outp) => cmp::max(outp.cltv_expiry, output_conf_height + 1),
 451                         PackageSolvingData::HolderFundingOutput(_) => output_conf_height + 1,
 452                 };
 453                 absolute_timelock
 454         }
 455 }
 456
 457 impl_writeable_tlv_based_enum!(PackageSolvingData, ;
 458         (0, RevokedOutput),
 459         (1, RevokedHTLCOutput),
 460         (2, CounterpartyOfferedHTLCOutput),
 461         (3, CounterpartyReceivedHTLCOutput),
 462         (4, HolderHTLCOutput),
 463         (5, HolderFundingOutput),
 464 );
 465
 466 /// A malleable package might be aggregated with other packages to save on fees.
 467 /// A untractable package has been counter-signed and aggregable will break cached counterparty
 468 /// signatures.
 469 #[derive(Clone, PartialEq, Eq)]
 470 pub(crate) enum PackageMalleability {
 471         Malleable,
 472         Untractable,
 473 }
 474
 475 /// A structure to describe a package content that is generated by ChannelMonitor and
 476 /// used by OnchainTxHandler to generate and broadcast transactions settling onchain claims.
 477 ///
 478 /// A package is defined as one or more transactions claiming onchain outputs in reaction
 479 /// to confirmation of a channel transaction. Those packages might be aggregated to save on
 480 /// fees, if satisfaction of outputs's witnessScript let's us do so.
 481 ///
 482 /// As packages are time-sensitive, we fee-bump and rebroadcast them at scheduled intervals.
 483 /// Failing to confirm a package translate as a loss of funds for the user.
 484 #[derive(Clone, PartialEq, Eq)]
 485 pub struct PackageTemplate {
 486         // List of onchain outputs and solving data to generate satisfying witnesses.
 487         inputs: Vec<(BitcoinOutPoint, PackageSolvingData)>,
 488         // Packages are deemed as malleable if we have local knwoledge of at least one set of
 489         // private keys yielding a satisfying witnesses. Malleability implies that we can aggregate
 490         // packages among them to save on fees or rely on RBF to bump their feerates.
 491         // Untractable packages have been counter-signed and thus imply that we can't aggregate
 492         // them without breaking signatures. Fee-bumping strategy will also rely on CPFP.
 493         malleability: PackageMalleability,
 494         // Block height after which the earlier-output belonging to this package is mature for a
 495         // competing claim by the counterparty. As our chain tip becomes nearer from the timelock,
 496         // the fee-bumping frequency will increase. See `OnchainTxHandler::get_height_timer`.
 497         soonest_conf_deadline: u32,
 498         // Determines if this package can be aggregated.
 499         // Timelocked outputs belonging to the same transaction might have differing
 500         // satisfying heights. Picking up the later height among the output set would be a valid
 501         // aggregable strategy but it comes with at least 2 trade-offs :
 502         // * earlier-output fund are going to take longer to come back
 503         // * CLTV delta backing up a corresponding HTLC on an upstream channel could be swallowed
 504         // by the requirement of the later-output part of the set
 505         // For now, we mark such timelocked outputs as non-aggregable, though we might introduce
 506         // smarter aggregable strategy in the future.
 507         aggregable: bool,
 508         // Cache of package feerate committed at previous (re)broadcast. If bumping resources
 509         // (either claimed output value or external utxo), it will keep increasing until holder
 510         // or counterparty successful claim.
 511         feerate_previous: u64,
 512         // Cache of next height at which fee-bumping and rebroadcast will be attempted. In
 513         // the future, we might abstract it to an observed mempool fluctuation.
 514         height_timer: Option<u32>,
 515         // Confirmation height of the claimed outputs set transaction. In case of reorg reaching
 516         // it, we wipe out and forget the package.
 517         height_original: u32,
 518 }
 519
 520 impl PackageTemplate {
 521         pub(crate) fn is_malleable(&self) -> bool {
 522                 self.malleability == PackageMalleability::Malleable
 523         }
 524         pub(crate) fn timelock(&self) -> u32 {
 525                 self.soonest_conf_deadline
 526         }
 527         pub(crate) fn aggregable(&self) -> bool {
 528                 self.aggregable
 529         }
 530         pub(crate) fn set_feerate(&mut self, new_feerate: u64) {
 531                 self.feerate_previous = new_feerate;
 532         }
 533         pub(crate) fn timer(&self) -> Option<u32> {
 534                 if let Some(ref timer) = self.height_timer {
 535                         return Some(*timer);
 536                 }
 537                 None
 538         }
 539         pub(crate) fn set_timer(&mut self, new_timer: Option<u32>) {
 540                 self.height_timer = new_timer;
 541         }
 542         pub(crate) fn outpoints(&self) -> Vec<&BitcoinOutPoint> {
 543                 self.inputs.iter().map(|(o, _)| o).collect()
 544         }
 545         pub(crate) fn split_package(&mut self, split_outp: &BitcoinOutPoint) -> Option<PackageTemplate> {
 546                 match self.malleability {
 547                         PackageMalleability::Malleable => {
 548                                 let mut split_package = None;
 549                                 let timelock = self.soonest_conf_deadline;
 550                                 let aggregable = self.aggregable;
 551                                 let feerate_previous = self.feerate_previous;
 552                                 let height_timer = self.height_timer;
 553                                 let height_original = self.height_original;
 554                                 self.inputs.retain(|outp| {
 555                                         if *split_outp == outp.0 {
 556                                                 split_package = Some(PackageTemplate {
 557                                                         inputs: vec![(outp.0, outp.1.clone())],
 558                                                         malleability: PackageMalleability::Malleable,
 559                                                         soonest_conf_deadline: timelock,
 560                                                         aggregable,
 561                                                         feerate_previous,
 562                                                         height_timer,
 563                                                         height_original,
 564                                                 });
 565                                                 return false;
 566                                         }
 567                                         return true;
 568                                 });
 569                                 return split_package;
 570                         },
 571                         _ => {
 572                                 // Note, we may try to split on remote transaction for
 573                                 // which we don't have a competing one (HTLC-Success before
 574                                 // timelock expiration). This explain we don't panic!
 575                                 // We should refactor OnchainTxHandler::block_connected to
 576                                 // only test equality on competing claims.
 577                                 return None;
 578                         }
 579                 }
 580         }
 581         pub(crate) fn merge_package(&mut self, mut merge_from: PackageTemplate) {
 582                 assert_eq!(self.height_original, merge_from.height_original);
 583                 if self.malleability == PackageMalleability::Untractable || merge_from.malleability == PackageMalleability::Untractable {
 584                         panic!("Merging template on untractable packages");
 585                 }
 586                 if !self.aggregable || !merge_from.aggregable {
 587                         panic!("Merging non aggregatable packages");
 588                 }
 589                 if let Some((_, lead_input)) = self.inputs.first() {
 590                         for (_, v) in merge_from.inputs.iter() {
 591                                 if !lead_input.is_compatible(v) { panic!("Merging outputs from differing types !"); }
 592                         }
 593                 } else { panic!("Merging template on an empty package"); }
 594                 for (k, v) in merge_from.inputs.drain(..) {
 595                         self.inputs.push((k, v));
 596                 }
 597                 //TODO: verify coverage and sanity?
 598                 if self.soonest_conf_deadline > merge_from.soonest_conf_deadline {
 599                         self.soonest_conf_deadline = merge_from.soonest_conf_deadline;
 600                 }
 601                 if self.feerate_previous > merge_from.feerate_previous {
 602                         self.feerate_previous = merge_from.feerate_previous;
 603                 }
 604                 self.height_timer = cmp::min(self.height_timer, merge_from.height_timer);
 605         }
 606         /// Gets the amount of all outptus being spent by this package, only valid for malleable
 607         /// packages.
 608         fn package_amount(&self) -> u64 {
 609                 let mut amounts = 0;
 610                 for (_, outp) in self.inputs.iter() {
 611                         amounts += outp.amount();
 612                 }
 613                 amounts
 614         }
 615         pub(crate) fn package_timelock(&self) -> u32 {
 616                 self.inputs.iter().map(|(_, outp)| outp.absolute_tx_timelock(self.height_original))
 617                         .max().expect("There must always be at least one output to spend in a PackageTemplate")
 618         }
 619         pub(crate) fn package_weight(&self, destination_script: &Script) -> usize {
 620                 let mut inputs_weight = 0;
 621                 let mut witnesses_weight = 2; // count segwit flags
 622                 for (_, outp) in self.inputs.iter() {
 623                         // previous_out_point: 36 bytes ; var_int: 1 byte ; sequence: 4 bytes
 624                         inputs_weight += 41 * WITNESS_SCALE_FACTOR;
 625                         witnesses_weight += outp.weight();
 626                 }
 627                 // version: 4 bytes ; count_tx_in: 1 byte ; count_tx_out: 1 byte ; lock_time: 4 bytes
 628                 let transaction_weight = 10 * WITNESS_SCALE_FACTOR;
 629                 // value: 8 bytes ; var_int: 1 byte ; pk_script: `destination_script.len()`
 630                 let output_weight = (8 + 1 + destination_script.len()) * WITNESS_SCALE_FACTOR;
 631                 inputs_weight + witnesses_weight + transaction_weight + output_weight
 632         }
 633         pub(crate) fn finalize_package<L: Deref, Signer: Sign>(&self, onchain_handler: &mut OnchainTxHandler<Signer>, value: u64, destination_script: Script, logger: &L) -> Option<Transaction>
 634                 where L::Target: Logger,
 635         {
 636                 match self.malleability {
 637                         PackageMalleability::Malleable => {
 638                                 let mut bumped_tx = Transaction {
 639                                         version: 2,
 640                                         lock_time: PackedLockTime::ZERO,
 641                                         input: vec![],
 642                                         output: vec![TxOut {
 643                                                 script_pubkey: destination_script,
 644                                                 value,
 645                                         }],
 646                                 };
 647                                 for (outpoint, _) in self.inputs.iter() {
 648                                         bumped_tx.input.push(TxIn {
 649                                                 previous_output: *outpoint,
 650                                                 script_sig: Script::new(),
 651                                                 sequence: Sequence::ENABLE_RBF_NO_LOCKTIME,
 652                                                 witness: Witness::new(),
 653                                         });
 654                                 }
 655                                 for (i, (outpoint, out)) in self.inputs.iter().enumerate() {
 656                                         log_debug!(logger, "Adding claiming input for outpoint {}:{}", outpoint.txid, outpoint.vout);
 657                                         if !out.finalize_input(&mut bumped_tx, i, onchain_handler) { return None; }
 658                                 }
 659                                 log_debug!(logger, "Finalized transaction {} ready to broadcast", bumped_tx.txid());
 660                                 return Some(bumped_tx);
 661                         },
 662                         PackageMalleability::Untractable => {
 663                                 debug_assert_eq!(value, 0, "value is ignored for non-malleable packages, should be zero to ensure callsites are correct");
 664                                 if let Some((outpoint, outp)) = self.inputs.first() {
 665                                         if let Some(final_tx) = outp.get_finalized_tx(outpoint, onchain_handler) {
 666                                                 log_debug!(logger, "Adding claiming input for outpoint {}:{}", outpoint.txid, outpoint.vout);
 667                                                 log_debug!(logger, "Finalized transaction {} ready to broadcast", final_tx.txid());
 668                                                 return Some(final_tx);
 669                                         }
 670                                         return None;
 671                                 } else { panic!("API Error: Package must not be inputs empty"); }
 672                         },
 673                 }
 674         }
 675         /// In LN, output claimed are time-sensitive, which means we have to spend them before reaching some timelock expiration. At in-channel
 676         /// 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
 677         /// height that once reached we should generate a new bumped "version" of the claim tx to be sure that we safely claim outputs before
 678         /// that our counterparty can do so. If timelock expires soon, height timer is going to be scaled down in consequence to increase
 679         /// frequency of the bump and so increase our bets of success.
 680         pub(crate) fn get_height_timer(&self, current_height: u32) -> u32 {
 681                 if self.soonest_conf_deadline <= current_height + MIDDLE_FREQUENCY_BUMP_INTERVAL {
 682                         return current_height + HIGH_FREQUENCY_BUMP_INTERVAL
 683                 } else if self.soonest_conf_deadline - current_height <= LOW_FREQUENCY_BUMP_INTERVAL {
 684                         return current_height + MIDDLE_FREQUENCY_BUMP_INTERVAL
 685                 }
 686                 current_height + LOW_FREQUENCY_BUMP_INTERVAL
 687         }
 688
 689         /// Returns value in satoshis to be included as package outgoing output amount and feerate
 690         /// which was used to generate the value. Will not return less than `dust_limit_sats` for the
 691         /// value.
 692         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)>
 693                 where F::Target: FeeEstimator,
 694                       L::Target: Logger,
 695         {
 696                 debug_assert!(self.malleability == PackageMalleability::Malleable, "The package output is fixed for non-malleable packages");
 697                 let input_amounts = self.package_amount();
 698                 assert!(dust_limit_sats as i64 > 0, "Output script must be broadcastable/have a 'real' dust limit.");
 699                 // If old feerate is 0, first iteration of this claim, use normal fee calculation
 700                 if self.feerate_previous != 0 {
 701                         if let Some((new_fee, feerate)) = feerate_bump(predicted_weight, input_amounts, self.feerate_previous, fee_estimator, logger) {
 702                                 return Some((cmp::max(input_amounts as i64 - new_fee as i64, dust_limit_sats as i64) as u64, feerate));
 703                         }
 704                 } else {
 705                         if let Some((new_fee, feerate)) = compute_fee_from_spent_amounts(input_amounts, predicted_weight, fee_estimator, logger) {
 706                                 return Some((cmp::max(input_amounts as i64 - new_fee as i64, dust_limit_sats as i64) as u64, feerate));
 707                         }
 708                 }
 709                 None
 710         }
 711         pub (crate) fn build_package(txid: Txid, vout: u32, input_solving_data: PackageSolvingData, soonest_conf_deadline: u32, aggregable: bool, height_original: u32) -> Self {
 712                 let malleability = match input_solving_data {
 713                         PackageSolvingData::RevokedOutput(..) => { PackageMalleability::Malleable },
 714                         PackageSolvingData::RevokedHTLCOutput(..) => { PackageMalleability::Malleable },
 715                         PackageSolvingData::CounterpartyOfferedHTLCOutput(..) => { PackageMalleability::Malleable },
 716                         PackageSolvingData::CounterpartyReceivedHTLCOutput(..) => { PackageMalleability::Malleable },
 717                         PackageSolvingData::HolderHTLCOutput(..) => { PackageMalleability::Untractable },
 718                         PackageSolvingData::HolderFundingOutput(..) => { PackageMalleability::Untractable },
 719                 };
 720                 let mut inputs = Vec::with_capacity(1);
 721                 inputs.push((BitcoinOutPoint { txid, vout }, input_solving_data));
 722                 PackageTemplate {
 723                         inputs,
 724                         malleability,
 725                         soonest_conf_deadline,
 726                         aggregable,
 727                         feerate_previous: 0,
 728                         height_timer: None,
 729                         height_original,
 730                 }
 731         }
 732 }
 733
 734 impl Writeable for PackageTemplate {
 735         fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 736                 writer.write_all(&byte_utils::be64_to_array(self.inputs.len() as u64))?;
 737                 for (ref outpoint, ref rev_outp) in self.inputs.iter() {
 738                         outpoint.write(writer)?;
 739                         rev_outp.write(writer)?;
 740                 }
 741                 write_tlv_fields!(writer, {
 742                         (0, self.soonest_conf_deadline, required),
 743                         (2, self.feerate_previous, required),
 744                         (4, self.height_original, required),
 745                         (6, self.height_timer, option)
 746                 });
 747                 Ok(())
 748         }
 749 }
 750
 751 impl Readable for PackageTemplate {
 752         fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
 753                 let inputs_count = <u64 as Readable>::read(reader)?;
 754                 let mut inputs: Vec<(BitcoinOutPoint, PackageSolvingData)> = Vec::with_capacity(cmp::min(inputs_count as usize, MAX_ALLOC_SIZE / 128));
 755                 for _ in 0..inputs_count {
 756                         let outpoint = Readable::read(reader)?;
 757                         let rev_outp = Readable::read(reader)?;
 758                         inputs.push((outpoint, rev_outp));
 759                 }
 760                 let (malleability, aggregable) = if let Some((_, lead_input)) = inputs.first() {
 761                         match lead_input {
 762                                 PackageSolvingData::RevokedOutput(..) => { (PackageMalleability::Malleable, true) },
 763                                 PackageSolvingData::RevokedHTLCOutput(..) => { (PackageMalleability::Malleable, true) },
 764                                 PackageSolvingData::CounterpartyOfferedHTLCOutput(..) => { (PackageMalleability::Malleable, true) },
 765                                 PackageSolvingData::CounterpartyReceivedHTLCOutput(..) => { (PackageMalleability::Malleable, false) },
 766                                 PackageSolvingData::HolderHTLCOutput(..) => { (PackageMalleability::Untractable, false) },
 767                                 PackageSolvingData::HolderFundingOutput(..) => { (PackageMalleability::Untractable, false) },
 768                         }
 769                 } else { return Err(DecodeError::InvalidValue); };
 770                 let mut soonest_conf_deadline = 0;
 771                 let mut feerate_previous = 0;
 772                 let mut height_timer = None;
 773                 let mut height_original = 0;
 774                 read_tlv_fields!(reader, {
 775                         (0, soonest_conf_deadline, required),
 776                         (2, feerate_previous, required),
 777                         (4, height_original, required),
 778                         (6, height_timer, option),
 779                 });
 780                 Ok(PackageTemplate {
 781                         inputs,
 782                         malleability,
 783                         soonest_conf_deadline,
 784                         aggregable,
 785                         feerate_previous,
 786                         height_timer,
 787                         height_original,
 788                 })
 789         }
 790 }
 791
 792 /// Attempt to propose a bumping fee for a transaction from its spent output's values and predicted
 793 /// weight. We start with the highest priority feerate returned by the node's fee estimator then
 794 /// fall-back to lower priorities until we have enough value available to suck from.
 795 ///
 796 /// If the proposed fee is less than the available spent output's values, we return the proposed
 797 /// fee and the corresponding updated feerate. If the proposed fee is equal or more than the
 798 /// available spent output's values, we return nothing
 799 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)>
 800         where F::Target: FeeEstimator,
 801               L::Target: Logger,
 802 {
 803         let mut updated_feerate = fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::HighPriority) as u64;
 804         let mut fee = updated_feerate * (predicted_weight as u64) / 1000;
 805         if input_amounts <= fee {
 806                 updated_feerate = fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Normal) as u64;
 807                 fee = updated_feerate * (predicted_weight as u64) / 1000;
 808                 if input_amounts <= fee {
 809                         updated_feerate = fee_estimator.bounded_sat_per_1000_weight(ConfirmationTarget::Background) as u64;
 810                         fee = updated_feerate * (predicted_weight as u64) / 1000;
 811                         if input_amounts <= fee {
 812                                 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)",
 813                                         fee, input_amounts);
 814                                 None
 815                         } else {
 816                                 log_warn!(logger, "Used low priority fee for on-chain punishment tx as high priority fee was more than the entire claim balance ({} sat)",
 817                                         input_amounts);
 818                                 Some((fee, updated_feerate))
 819                         }
 820                 } else {
 821                         log_warn!(logger, "Used medium 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                 Some((fee, updated_feerate))
 827         }
 828 }
 829
 830 /// Attempt to propose a bumping fee for a transaction from its spent output's values and predicted
 831 /// weight. If feerates proposed by the fee-estimator have been increasing since last fee-bumping
 832 /// attempt, use them. Otherwise, blindly bump the feerate by 25% of the previous feerate. We also
 833 /// verify that those bumping heuristics respect BIP125 rules 3) and 4) and if required adjust
 834 /// the new fee to meet the RBF policy requirement.
 835 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)>
 836         where F::Target: FeeEstimator,
 837               L::Target: Logger,
 838 {
 839         // If old feerate inferior to actual one given back by Fee Estimator, use it to compute new fee...
 840         let new_fee = if let Some((new_fee, _)) = compute_fee_from_spent_amounts(input_amounts, predicted_weight, fee_estimator, logger) {
 841                 let updated_feerate = new_fee / (predicted_weight as u64 * 1000);
 842                 if updated_feerate > previous_feerate {
 843                         new_fee
 844                 } else {
 845                         // ...else just increase the previous feerate by 25% (because that's a nice number)
 846                         let new_fee = previous_feerate * (predicted_weight as u64) / 750;
 847                         if input_amounts <= new_fee {
 848                                 log_warn!(logger, "Can't 25% bump new claiming tx, amount {} is too small", input_amounts);
 849                                 return None;
 850                         }
 851                         new_fee
 852                 }
 853         } else {
 854                 log_warn!(logger, "Can't new-estimation bump new claiming tx, amount {} is too small", input_amounts);
 855                 return None;
 856         };
 857
 858         let previous_fee = previous_feerate * (predicted_weight as u64) / 1000;
 859         let min_relay_fee = MIN_RELAY_FEE_SAT_PER_1000_WEIGHT * (predicted_weight as u64) / 1000;
 860         // BIP 125 Opt-in Full Replace-by-Fee Signaling
 861         //      * 3. The replacement transaction pays an absolute fee of at least the sum paid by the original transactions.
 862         //      * 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.
 863         let new_fee = if new_fee < previous_fee + min_relay_fee {
 864                 new_fee + previous_fee + min_relay_fee - new_fee
 865         } else {
 866                 new_fee
 867         };
 868         Some((new_fee, new_fee * 1000 / (predicted_weight as u64)))
 869 }
 870
 871 #[cfg(test)]
 872 mod tests {
 873         use chain::package::{CounterpartyOfferedHTLCOutput, CounterpartyReceivedHTLCOutput, HolderHTLCOutput, PackageTemplate, PackageSolvingData, RevokedOutput, WEIGHT_REVOKED_OUTPUT, weight_offered_htlc, weight_received_htlc};
 874         use chain::Txid;
 875         use ln::chan_utils::HTLCOutputInCommitment;
 876         use ln::{PaymentPreimage, PaymentHash};
 877
 878         use bitcoin::blockdata::constants::WITNESS_SCALE_FACTOR;
 879         use bitcoin::blockdata::script::Script;
 880         use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
 881
 882         use bitcoin::hashes::hex::FromHex;
 883
 884         use bitcoin::secp256k1::{PublicKey,SecretKey};
 885         use bitcoin::secp256k1::Secp256k1;
 886
 887         macro_rules! dumb_revk_output {
 888                 ($secp_ctx: expr) => {
 889                         {
 890                                 let dumb_scalar = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
 891                                 let dumb_point = PublicKey::from_secret_key(&$secp_ctx, &dumb_scalar);
 892                                 PackageSolvingData::RevokedOutput(RevokedOutput::build(dumb_point, dumb_point, dumb_point, dumb_scalar, 0, 0))
 893                         }
 894                 }
 895         }
 896
 897         macro_rules! dumb_counterparty_output {
 898                 ($secp_ctx: expr, $amt: expr, $opt_anchors: expr) => {
 899                         {
 900                                 let dumb_scalar = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
 901                                 let dumb_point = PublicKey::from_secret_key(&$secp_ctx, &dumb_scalar);
 902                                 let hash = PaymentHash([1; 32]);
 903                                 let htlc = HTLCOutputInCommitment { offered: true, amount_msat: $amt, cltv_expiry: 0, payment_hash: hash, transaction_output_index: None };
 904                                 PackageSolvingData::CounterpartyReceivedHTLCOutput(CounterpartyReceivedHTLCOutput::build(dumb_point, dumb_point, dumb_point, htlc, $opt_anchors))
 905                         }
 906                 }
 907         }
 908
 909         macro_rules! dumb_counterparty_offered_output {
 910                 ($secp_ctx: expr, $amt: expr, $opt_anchors: expr) => {
 911                         {
 912                                 let dumb_scalar = SecretKey::from_slice(&hex::decode("0101010101010101010101010101010101010101010101010101010101010101").unwrap()[..]).unwrap();
 913                                 let dumb_point = PublicKey::from_secret_key(&$secp_ctx, &dumb_scalar);
 914                                 let hash = PaymentHash([1; 32]);
 915                                 let preimage = PaymentPreimage([2;32]);
 916                                 let htlc = HTLCOutputInCommitment { offered: false, amount_msat: $amt, cltv_expiry: 1000, payment_hash: hash, transaction_output_index: None };
 917                                 PackageSolvingData::CounterpartyOfferedHTLCOutput(CounterpartyOfferedHTLCOutput::build(dumb_point, dumb_point, dumb_point, preimage, htlc, $opt_anchors))
 918                         }
 919                 }
 920         }
 921
 922         macro_rules! dumb_htlc_output {
 923                 () => {
 924                         {
 925                                 let preimage = PaymentPreimage([2;32]);
 926                                 PackageSolvingData::HolderHTLCOutput(HolderHTLCOutput::build_accepted(preimage, 0))
 927                         }
 928                 }
 929         }
 930
 931         #[test]
 932         #[should_panic]
 933         fn test_package_differing_heights() {
 934                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
 935                 let secp_ctx = Secp256k1::new();
 936                 let revk_outp = dumb_revk_output!(secp_ctx);
 937
 938                 let mut package_one_hundred = PackageTemplate::build_package(txid, 0, revk_outp.clone(), 1000, true, 100);
 939                 let package_two_hundred = PackageTemplate::build_package(txid, 1, revk_outp.clone(), 1000, true, 200);
 940                 package_one_hundred.merge_package(package_two_hundred);
 941         }
 942
 943         #[test]
 944         #[should_panic]
 945         fn test_package_untractable_merge_to() {
 946                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
 947                 let secp_ctx = Secp256k1::new();
 948                 let revk_outp = dumb_revk_output!(secp_ctx);
 949                 let htlc_outp = dumb_htlc_output!();
 950
 951                 let mut untractable_package = PackageTemplate::build_package(txid, 0, revk_outp.clone(), 1000, true, 100);
 952                 let malleable_package = PackageTemplate::build_package(txid, 1, htlc_outp.clone(), 1000, true, 100);
 953                 untractable_package.merge_package(malleable_package);
 954         }
 955
 956         #[test]
 957         #[should_panic]
 958         fn test_package_untractable_merge_from() {
 959                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
 960                 let secp_ctx = Secp256k1::new();
 961                 let htlc_outp = dumb_htlc_output!();
 962                 let revk_outp = dumb_revk_output!(secp_ctx);
 963
 964                 let mut malleable_package = PackageTemplate::build_package(txid, 0, htlc_outp.clone(), 1000, true, 100);
 965                 let untractable_package = PackageTemplate::build_package(txid, 1, revk_outp.clone(), 1000, true, 100);
 966                 malleable_package.merge_package(untractable_package);
 967         }
 968
 969         #[test]
 970         #[should_panic]
 971         fn test_package_noaggregation_to() {
 972                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
 973                 let secp_ctx = Secp256k1::new();
 974                 let revk_outp = dumb_revk_output!(secp_ctx);
 975
 976                 let mut noaggregation_package = PackageTemplate::build_package(txid, 0, revk_outp.clone(), 1000, false, 100);
 977                 let aggregation_package = PackageTemplate::build_package(txid, 1, revk_outp.clone(), 1000, true, 100);
 978                 noaggregation_package.merge_package(aggregation_package);
 979         }
 980
 981         #[test]
 982         #[should_panic]
 983         fn test_package_noaggregation_from() {
 984                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
 985                 let secp_ctx = Secp256k1::new();
 986                 let revk_outp = dumb_revk_output!(secp_ctx);
 987
 988                 let mut aggregation_package = PackageTemplate::build_package(txid, 0, revk_outp.clone(), 1000, true, 100);
 989                 let noaggregation_package = PackageTemplate::build_package(txid, 1, revk_outp.clone(), 1000, false, 100);
 990                 aggregation_package.merge_package(noaggregation_package);
 991         }
 992
 993         #[test]
 994         #[should_panic]
 995         fn test_package_empty() {
 996                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
 997                 let secp_ctx = Secp256k1::new();
 998                 let revk_outp = dumb_revk_output!(secp_ctx);
 999
1000                 let mut empty_package = PackageTemplate::build_package(txid, 0, revk_outp.clone(), 1000, true, 100);
1001                 empty_package.inputs = vec![];
1002                 let package = PackageTemplate::build_package(txid, 1, revk_outp.clone(), 1000, true, 100);
1003                 empty_package.merge_package(package);
1004         }
1005
1006         #[test]
1007         #[should_panic]
1008         fn test_package_differing_categories() {
1009                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1010                 let secp_ctx = Secp256k1::new();
1011                 let revk_outp = dumb_revk_output!(secp_ctx);
1012                 let counterparty_outp = dumb_counterparty_output!(secp_ctx, 0, false);
1013
1014                 let mut revoked_package = PackageTemplate::build_package(txid, 0, revk_outp, 1000, true, 100);
1015                 let counterparty_package = PackageTemplate::build_package(txid, 1, counterparty_outp, 1000, true, 100);
1016                 revoked_package.merge_package(counterparty_package);
1017         }
1018
1019         #[test]
1020         fn test_package_split_malleable() {
1021                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1022                 let secp_ctx = Secp256k1::new();
1023                 let revk_outp_one = dumb_revk_output!(secp_ctx);
1024                 let revk_outp_two = dumb_revk_output!(secp_ctx);
1025                 let revk_outp_three = dumb_revk_output!(secp_ctx);
1026
1027                 let mut package_one = PackageTemplate::build_package(txid, 0, revk_outp_one, 1000, true, 100);
1028                 let package_two = PackageTemplate::build_package(txid, 1, revk_outp_two, 1000, true, 100);
1029                 let package_three = PackageTemplate::build_package(txid, 2, revk_outp_three, 1000, true, 100);
1030
1031                 package_one.merge_package(package_two);
1032                 package_one.merge_package(package_three);
1033                 assert_eq!(package_one.outpoints().len(), 3);
1034
1035                 if let Some(split_package) = package_one.split_package(&BitcoinOutPoint { txid, vout: 1 }) {
1036                         // Packages attributes should be identical
1037                         assert!(split_package.is_malleable());
1038                         assert_eq!(split_package.soonest_conf_deadline, package_one.soonest_conf_deadline);
1039                         assert_eq!(split_package.aggregable, package_one.aggregable);
1040                         assert_eq!(split_package.feerate_previous, package_one.feerate_previous);
1041                         assert_eq!(split_package.height_timer, package_one.height_timer);
1042                         assert_eq!(split_package.height_original, package_one.height_original);
1043                 } else { panic!(); }
1044                 assert_eq!(package_one.outpoints().len(), 2);
1045         }
1046
1047         #[test]
1048         fn test_package_split_untractable() {
1049                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1050                 let htlc_outp_one = dumb_htlc_output!();
1051
1052                 let mut package_one = PackageTemplate::build_package(txid, 0, htlc_outp_one, 1000, true, 100);
1053                 let ret_split = package_one.split_package(&BitcoinOutPoint { txid, vout: 0});
1054                 assert!(ret_split.is_none());
1055         }
1056
1057         #[test]
1058         fn test_package_timer() {
1059                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1060                 let secp_ctx = Secp256k1::new();
1061                 let revk_outp = dumb_revk_output!(secp_ctx);
1062
1063                 let mut package = PackageTemplate::build_package(txid, 0, revk_outp, 1000, true, 100);
1064                 let timer_none = package.timer();
1065                 assert!(timer_none.is_none());
1066                 package.set_timer(Some(100));
1067                 if let Some(timer_some) = package.timer() {
1068                         assert_eq!(timer_some, 100);
1069                 } else { panic!() }
1070         }
1071
1072         #[test]
1073         fn test_package_amounts() {
1074                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1075                 let secp_ctx = Secp256k1::new();
1076                 let counterparty_outp = dumb_counterparty_output!(secp_ctx, 1_000_000, false);
1077
1078                 let package = PackageTemplate::build_package(txid, 0, counterparty_outp, 1000, true, 100);
1079                 assert_eq!(package.package_amount(), 1000);
1080         }
1081
1082         #[test]
1083         fn test_package_weight() {
1084                 let txid = Txid::from_hex("c2d4449afa8d26140898dd54d3390b057ba2a5afcf03ba29d7dc0d8b9ffe966e").unwrap();
1085                 let secp_ctx = Secp256k1::new();
1086
1087                 // (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)
1088                 let weight_sans_output = (4 + 4 + 1 + 36 + 4 + 1 + 1 + 8 + 1) * WITNESS_SCALE_FACTOR + 2;
1089
1090                 {
1091                         let revk_outp = dumb_revk_output!(secp_ctx);
1092                         let package = PackageTemplate::build_package(txid, 0, revk_outp, 0, true, 100);
1093                         assert_eq!(package.package_weight(&Script::new()),  weight_sans_output + WEIGHT_REVOKED_OUTPUT as usize);
1094                 }
1095
1096                 {
1097                         for &opt_anchors in [false, true].iter() {
1098                                 let counterparty_outp = dumb_counterparty_output!(secp_ctx, 1_000_000, opt_anchors);
1099                                 let package = PackageTemplate::build_package(txid, 0, counterparty_outp, 1000, true, 100);
1100                                 assert_eq!(package.package_weight(&Script::new()), weight_sans_output + weight_received_htlc(opt_anchors) as usize);
1101                         }
1102                 }
1103
1104                 {
1105                         for &opt_anchors in [false, true].iter() {
1106                                 let counterparty_outp = dumb_counterparty_offered_output!(secp_ctx, 1_000_000, opt_anchors);
1107                                 let package = PackageTemplate::build_package(txid, 0, counterparty_outp, 1000, true, 100);
1108                                 assert_eq!(package.package_weight(&Script::new()), weight_sans_output + weight_offered_htlc(opt_anchors) as usize);
1109                         }
1110                 }
1111         }
1112 }