-//! Utilities for computing witnesses weight and feerate computation for onchain operation
+// This file is Copyright its original authors, visible in version control
+// history.
+//
+// This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
+// or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
+// You may not use this file except in accordance with one or both of these
+// licenses.
+//! Various utilities to assemble claimable outpoints in package of one or more transactions. Those
+//! packages are attached metadata, guiding their aggregable or fee-bumping re-schedule. This file
+//! also includes witness weight computation and fee computation methods.
+
+use bitcoin::blockdata::constants::WITNESS_SCALE_FACTOR;
+use bitcoin::blockdata::transaction::{TxOut,TxIn, Transaction, SigHashType};
+use bitcoin::blockdata::transaction::OutPoint as BitcoinOutPoint;
+use bitcoin::blockdata::script::Script;
+
+use bitcoin::hash_types::Txid;
+
+use bitcoin::secp256k1::key::{SecretKey,PublicKey};
+
+use ln::PaymentPreimage;
+use ln::chan_utils::{TxCreationKeys, HTLCOutputInCommitment, HTLC_OUTPUT_IN_COMMITMENT_SIZE};
+use ln::chan_utils;
use ln::msgs::DecodeError;
+use ln::onchaintx::OnchainTxHandler;
+use chain::keysinterface::Sign;
+use util::byte_utils;
+use util::logger::Logger;
use util::ser::{Readable, Writer, Writeable};
+use std::cmp;
+use std::mem;
+use std::ops::Deref;
+
+const MAX_ALLOC_SIZE: usize = 64*1024;
+
+
+// number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
+pub(crate) const WEIGHT_REVOKED_OFFERED_HTLC: u64 = 1 + 1 + 73 + 1 + 33 + 1 + 133;
+// number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
+pub(crate) const WEIGHT_REVOKED_RECEIVED_HTLC: u64 = 1 + 1 + 73 + 1 + 33 + 1 + 139;
+// number_of_witness_elements + sig_length + counterpartyhtlc_sig + preimage_length + preimage + witness_script_length + witness_script
+pub(crate) const WEIGHT_OFFERED_HTLC: u64 = 1 + 1 + 73 + 1 + 32 + 1 + 133;
+// number_of_witness_elements + sig_length + revocation_sig + pubkey_length + revocationpubkey + witness_script_length + witness_script
+pub(crate) const WEIGHT_RECEIVED_HTLC: u64 = 1 + 1 + 73 + 1 + 1 + 1 + 139;
+// number_of_witness_elements + sig_length + revocation_sig + true_length + op_true + witness_script_length + witness_script
+pub(crate) const WEIGHT_REVOKED_OUTPUT: u64 = 1 + 1 + 73 + 1 + 1 + 1 + 77;
+
+/// A struct to describe a revoked output and corresponding information to generate a solving
+/// witness spending a commitment `to_local` output or a second-stage HTLC transaction output.
+///
+/// CSV and pubkeys are used as part of a witnessScript redeeming a balance output, amount is used
+/// as part of the signature hash and revocation secret to generate a satisfying witness.
+#[derive(Clone, PartialEq)]
+pub(crate) struct RevokedOutput {
+ per_commitment_point: PublicKey,
+ counterparty_delayed_payment_base_key: PublicKey,
+ counterparty_htlc_base_key: PublicKey,
+ per_commitment_key: SecretKey,
+ weight: u64,
+ amount: u64,
+ on_counterparty_tx_csv: u16,
+}
+
+impl RevokedOutput {
+ 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 {
+ RevokedOutput {
+ per_commitment_point,
+ counterparty_delayed_payment_base_key,
+ counterparty_htlc_base_key,
+ per_commitment_key,
+ weight: WEIGHT_REVOKED_OUTPUT,
+ amount,
+ on_counterparty_tx_csv
+ }
+ }
+}
+
+impl_writeable!(RevokedOutput, 33*3 + 32 + 8 + 8 + 2, {
+ per_commitment_point,
+ counterparty_delayed_payment_base_key,
+ counterparty_htlc_base_key,
+ per_commitment_key,
+ weight,
+ amount,
+ on_counterparty_tx_csv
+});
+
+/// A struct to describe a revoked offered output and corresponding information to generate a
+/// solving witness.
+///
+/// HTLCOuputInCommitment (hash timelock, direction) and pubkeys are used to generate a suitable
+/// witnessScript.
+///
+/// CSV is used as part of a witnessScript redeeming a balance output, amount is used as part
+/// of the signature hash and revocation secret to generate a satisfying witness.
+#[derive(Clone, PartialEq)]
+pub(crate) struct RevokedHTLCOutput {
+ per_commitment_point: PublicKey,
+ counterparty_delayed_payment_base_key: PublicKey,
+ counterparty_htlc_base_key: PublicKey,
+ per_commitment_key: SecretKey,
+ weight: u64,
+ amount: u64,
+ htlc: HTLCOutputInCommitment,
+}
+
+impl RevokedHTLCOutput {
+ 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) -> Self {
+ let weight = if htlc.offered { WEIGHT_REVOKED_OFFERED_HTLC } else { WEIGHT_REVOKED_RECEIVED_HTLC };
+ RevokedHTLCOutput {
+ per_commitment_point,
+ counterparty_delayed_payment_base_key,
+ counterparty_htlc_base_key,
+ per_commitment_key,
+ weight,
+ amount,
+ htlc
+ }
+ }
+}
+
+impl_writeable!(RevokedHTLCOutput, 33*3 + 32 + 8 + 8 + HTLC_OUTPUT_IN_COMMITMENT_SIZE, {
+ per_commitment_point,
+ counterparty_delayed_payment_base_key,
+ counterparty_htlc_base_key,
+ per_commitment_key,
+ weight,
+ amount,
+ htlc
+});
+
+/// A struct to describe a HTLC output on a counterparty commitment transaction.
+///
+/// HTLCOutputInCommitment (hash, timelock, directon) and pubkeys are used to generate a suitable
+/// witnessScript.
+///
+/// The preimage is used as part of the witness.
+#[derive(Clone, PartialEq)]
+pub(crate) struct CounterpartyOfferedHTLCOutput {
+ per_commitment_point: PublicKey,
+ counterparty_delayed_payment_base_key: PublicKey,
+ counterparty_htlc_base_key: PublicKey,
+ preimage: PaymentPreimage,
+ htlc: HTLCOutputInCommitment
+}
+
+impl CounterpartyOfferedHTLCOutput {
+ pub(crate) fn build(per_commitment_point: PublicKey, counterparty_delayed_payment_base_key: PublicKey, counterparty_htlc_base_key: PublicKey, preimage: PaymentPreimage, htlc: HTLCOutputInCommitment) -> Self {
+ CounterpartyOfferedHTLCOutput {
+ per_commitment_point,
+ counterparty_delayed_payment_base_key,
+ counterparty_htlc_base_key,
+ preimage,
+ htlc
+ }
+ }
+}
+
+impl_writeable!(CounterpartyOfferedHTLCOutput, 33*3 + 32 + HTLC_OUTPUT_IN_COMMITMENT_SIZE, {
+ per_commitment_point,
+ counterparty_delayed_payment_base_key,
+ counterparty_htlc_base_key,
+ preimage,
+ htlc
+});
+
+/// A struct to describe a HTLC output on a counterparty commitment transaction.
+///
+/// HTLCOutputInCommitment (hash, timelock, directon) and pubkeys are used to generate a suitable
+/// witnessScript.
+#[derive(Clone, PartialEq)]
+pub(crate) struct CounterpartyReceivedHTLCOutput {
+ per_commitment_point: PublicKey,
+ counterparty_delayed_payment_base_key: PublicKey,
+ counterparty_htlc_base_key: PublicKey,
+ htlc: HTLCOutputInCommitment
+}
+
+impl CounterpartyReceivedHTLCOutput {
+ pub(crate) fn build(per_commitment_point: PublicKey, counterparty_delayed_payment_base_key: PublicKey, counterparty_htlc_base_key: PublicKey, htlc: HTLCOutputInCommitment) -> Self {
+ CounterpartyReceivedHTLCOutput {
+ per_commitment_point,
+ counterparty_delayed_payment_base_key,
+ counterparty_htlc_base_key,
+ htlc
+ }
+ }
+}
+
+impl_writeable!(CounterpartyReceivedHTLCOutput, 33*3 + HTLC_OUTPUT_IN_COMMITMENT_SIZE, {
+ per_commitment_point,
+ counterparty_delayed_payment_base_key,
+ counterparty_htlc_base_key,
+ htlc
+});
+
+/// A struct to describe a HTLC output on holder commitment transaction.
+///
+/// Either offered or received, the amount is always used as part of the bip143 sighash.
+/// Preimage is only included as part of the witness in former case.
+#[derive(Clone, PartialEq)]
+pub(crate) struct HolderHTLCOutput {
+ preimage: Option<PaymentPreimage>,
+ amount: u64,
+}
+
+impl HolderHTLCOutput {
+ pub(crate) fn build(preimage: Option<PaymentPreimage>, amount: u64) -> Self {
+ HolderHTLCOutput {
+ preimage,
+ amount
+ }
+ }
+}
+
+impl_writeable!(HolderHTLCOutput, 0, {
+ preimage,
+ amount
+});
+
+/// A struct to describe the channel output on the funding transaction.
+///
+/// witnessScript is used as part of the witness redeeming the funding utxo.
+#[derive(Clone, PartialEq)]
+pub(crate) struct HolderFundingOutput {
+ funding_redeemscript: Script,
+}
+
+impl HolderFundingOutput {
+ pub(crate) fn build(funding_redeemscript: Script) -> Self {
+ HolderFundingOutput {
+ funding_redeemscript,
+ }
+ }
+}
+
+impl_writeable!(HolderFundingOutput, 0, {
+ funding_redeemscript
+});
+
+/// A wrapper encapsulating all in-protocol differing outputs types.
+///
+/// The generic API offers access to an outputs common attributes or allow transformation such as
+/// finalizing an input claiming the output.
+#[derive(Clone, PartialEq)]
+pub(crate) enum PackageSolvingData {
+ RevokedOutput(RevokedOutput),
+ RevokedHTLCOutput(RevokedHTLCOutput),
+ CounterpartyOfferedHTLCOutput(CounterpartyOfferedHTLCOutput),
+ CounterpartyReceivedHTLCOutput(CounterpartyReceivedHTLCOutput),
+ HolderHTLCOutput(HolderHTLCOutput),
+ HolderFundingOutput(HolderFundingOutput),
+}
+
+impl PackageSolvingData {
+ fn amount(&self) -> u64 {
+ let amt = match self {
+ PackageSolvingData::RevokedOutput(ref outp) => { outp.amount },
+ PackageSolvingData::RevokedHTLCOutput(ref outp) => { outp.amount },
+ PackageSolvingData::CounterpartyOfferedHTLCOutput(ref outp) => { outp.htlc.amount_msat / 1000 },
+ PackageSolvingData::CounterpartyReceivedHTLCOutput(ref outp) => { outp.htlc.amount_msat / 1000 },
+ // Note: Currently, amounts of holder outputs spending witnesses aren't used
+ // as we can't malleate spending package to increase their feerate. This
+ // should change with the remaining anchor output patchset.
+ PackageSolvingData::HolderHTLCOutput(..) => { 0 },
+ PackageSolvingData::HolderFundingOutput(..) => { 0 },
+ };
+ amt
+ }
+ fn weight(&self) -> usize {
+ let weight = match self {
+ PackageSolvingData::RevokedOutput(ref outp) => { outp.weight as usize },
+ PackageSolvingData::RevokedHTLCOutput(ref outp) => { outp.weight as usize },
+ PackageSolvingData::CounterpartyOfferedHTLCOutput(..) => { WEIGHT_OFFERED_HTLC as usize },
+ PackageSolvingData::CounterpartyReceivedHTLCOutput(..) => { WEIGHT_RECEIVED_HTLC as usize },
+ // Note: Currently, weights of holder outputs spending witnesses aren't used
+ // as we can't malleate spending package to increase their feerate. This
+ // should change with the remaining anchor output patchset.
+ PackageSolvingData::HolderHTLCOutput(..) => { debug_assert!(false); 0 },
+ PackageSolvingData::HolderFundingOutput(..) => { debug_assert!(false); 0 },
+ };
+ weight
+ }
+ fn is_compatible(&self, input: &PackageSolvingData) -> bool {
+ match self {
+ PackageSolvingData::RevokedOutput(..) => {
+ match input {
+ PackageSolvingData::RevokedHTLCOutput(..) => { true },
+ PackageSolvingData::RevokedOutput(..) => { true },
+ _ => { false }
+ }
+ },
+ PackageSolvingData::RevokedHTLCOutput(..) => {
+ match input {
+ PackageSolvingData::RevokedOutput(..) => { true },
+ PackageSolvingData::RevokedHTLCOutput(..) => { true },
+ _ => { false }
+ }
+ },
+ _ => { mem::discriminant(self) == mem::discriminant(&input) }
+ }
+ }
+ fn finalize_input<Signer: Sign>(&self, bumped_tx: &mut Transaction, i: usize, onchain_handler: &mut OnchainTxHandler<Signer>) -> bool {
+ match self {
+ PackageSolvingData::RevokedOutput(ref outp) => {
+ 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) {
+ let witness_script = chan_utils::get_revokeable_redeemscript(&chan_keys.revocation_key, outp.on_counterparty_tx_csv, &chan_keys.broadcaster_delayed_payment_key);
+ //TODO: should we panic on signer failure ?
+ if let Ok(sig) = onchain_handler.signer.sign_justice_revoked_output(&bumped_tx, i, outp.amount, &outp.per_commitment_key, &onchain_handler.secp_ctx) {
+ bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
+ bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
+ bumped_tx.input[i].witness.push(vec!(1));
+ bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
+ } else { return false; }
+ }
+ },
+ PackageSolvingData::RevokedHTLCOutput(ref outp) => {
+ 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) {
+ let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&outp.htlc, &chan_keys.broadcaster_htlc_key, &chan_keys.countersignatory_htlc_key, &chan_keys.revocation_key);
+ //TODO: should we panic on signer failure ?
+ 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) {
+ bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
+ bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
+ bumped_tx.input[i].witness.push(chan_keys.revocation_key.clone().serialize().to_vec());
+ bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
+ } else { return false; }
+ }
+ },
+ PackageSolvingData::CounterpartyOfferedHTLCOutput(ref outp) => {
+ 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) {
+ let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&outp.htlc, &chan_keys.broadcaster_htlc_key, &chan_keys.countersignatory_htlc_key, &chan_keys.revocation_key);
+
+ 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) {
+ bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
+ bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
+ bumped_tx.input[i].witness.push(outp.preimage.0.to_vec());
+ bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
+ }
+ }
+ },
+ PackageSolvingData::CounterpartyReceivedHTLCOutput(ref outp) => {
+ 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) {
+ let witness_script = chan_utils::get_htlc_redeemscript_with_explicit_keys(&outp.htlc, &chan_keys.broadcaster_htlc_key, &chan_keys.countersignatory_htlc_key, &chan_keys.revocation_key);
+
+ bumped_tx.lock_time = 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
+ 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) {
+ bumped_tx.input[i].witness.push(sig.serialize_der().to_vec());
+ bumped_tx.input[i].witness[0].push(SigHashType::All as u8);
+ // Due to BIP146 (MINIMALIF) this must be a zero-length element to relay.
+ bumped_tx.input[i].witness.push(vec![]);
+ bumped_tx.input[i].witness.push(witness_script.clone().into_bytes());
+ }
+ }
+ },
+ _ => { panic!("API Error!"); }
+ }
+ true
+ }
+ fn get_finalized_tx<Signer: Sign>(&self, outpoint: &BitcoinOutPoint, onchain_handler: &mut OnchainTxHandler<Signer>) -> Option<Transaction> {
+ match self {
+ PackageSolvingData::HolderHTLCOutput(ref outp) => { return onchain_handler.get_fully_signed_htlc_tx(outpoint, &outp.preimage); }
+ PackageSolvingData::HolderFundingOutput(ref outp) => { return Some(onchain_handler.get_fully_signed_holder_tx(&outp.funding_redeemscript)); }
+ _ => { panic!("API Error!"); }
+ }
+ }
+}
+
+impl Writeable for PackageSolvingData {
+ fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
+ match self {
+ PackageSolvingData::RevokedOutput(ref revoked_outp) => {
+ 0u8.write(writer)?;
+ revoked_outp.write(writer)?;
+ },
+ PackageSolvingData::RevokedHTLCOutput(ref revoked_outp) => {
+ 1u8.write(writer)?;
+ revoked_outp.write(writer)?;
+ },
+ PackageSolvingData::CounterpartyOfferedHTLCOutput(ref counterparty_outp) => {
+ 2u8.write(writer)?;
+ counterparty_outp.write(writer)?;
+ },
+ PackageSolvingData::CounterpartyReceivedHTLCOutput(ref counterparty_outp) => {
+ 3u8.write(writer)?;
+ counterparty_outp.write(writer)?;
+ },
+ PackageSolvingData::HolderHTLCOutput(ref holder_outp) => {
+ 4u8.write(writer)?;
+ holder_outp.write(writer)?;
+ },
+ PackageSolvingData::HolderFundingOutput(ref funding_outp) => {
+ 5u8.write(writer)?;
+ funding_outp.write(writer)?;
+ }
+ }
+ Ok(())
+ }
+}
+
+impl Readable for PackageSolvingData {
+ fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
+ let byte = <u8 as Readable>::read(reader)?;
+ let solving_data = match byte {
+ 0 => {
+ PackageSolvingData::RevokedOutput(Readable::read(reader)?)
+ },
+ 1 => {
+ PackageSolvingData::RevokedHTLCOutput(Readable::read(reader)?)
+ },
+ 2 => {
+ PackageSolvingData::CounterpartyOfferedHTLCOutput(Readable::read(reader)?)
+ },
+ 3 => {
+ PackageSolvingData::CounterpartyReceivedHTLCOutput(Readable::read(reader)?)
+ },
+ 4 => {
+ PackageSolvingData::HolderHTLCOutput(Readable::read(reader)?)
+ },
+ 5 => {
+ PackageSolvingData::HolderFundingOutput(Readable::read(reader)?)
+ }
+ _ => return Err(DecodeError::UnknownVersion)
+ };
+ Ok(solving_data)
+ }
+}
+
+/// A malleable package might be aggregated with other packages to save on fees.
+/// A untractable package has been counter-signed and aggregable will break cached counterparty
+/// signatures.
+#[derive(Clone, PartialEq)]
+pub(crate) enum PackageMalleability {
+ Malleable,
+ Untractable,
+}
+
+/// A structure to describe a package content that is generated by ChannelMonitor and
+/// used by OnchainTxHandler to generate and broadcast transactions settling onchain claims.
+///
+/// A package is defined as one or more transactions claiming onchain outputs in reaction
+/// to confirmation of a channel transaction. Those packages might be aggregated to save on
+/// fees, if satisfaction of outputs's witnessScript let's us do so.
+///
+/// As packages are time-sensitive, we fee-bump and rebroadcast them at scheduled intervals.
+/// Failing to confirm a package translate as a loss of funds for the user.
+#[derive(Clone, PartialEq)]
+pub struct PackageTemplate {
+ // List of onchain outputs and solving data to generate satisfying witnesses.
+ inputs: Vec<(BitcoinOutPoint, PackageSolvingData)>,
+ // Packages are deemed as malleable if we have local knwoledge of at least one set of
+ // private keys yielding a satisfying witnesses. Malleability implies that we can aggregate
+ // packages among them to save on fees or rely on RBF to bump their feerates.
+ // Untractable packages have been counter-signed and thus imply that we can't aggregate
+ // them without breaking signatures. Fee-bumping strategy will also rely on CPFP.
+ malleability: PackageMalleability,
+ // Block height after which the earlier-output belonging to this package is mature for a
+ // competing claim by the counterparty. As our chain tip becomes nearer from the timelock,
+ // the fee-bumping frequency will increase. See `OnchainTxHandler::get_height_timer`.
+ soonest_conf_deadline: u32,
+ // Determines if this package can be aggregated.
+ // Timelocked outputs belonging to the same transaction might have differing
+ // satisfying heights. Picking up the later height among the output set would be a valid
+ // aggregable strategy but it comes with at least 2 trade-offs :
+ // * earlier-output fund are going to take longer to come back
+ // * CLTV delta backing up a corresponding HTLC on an upstream channel could be swallowed
+ // by the requirement of the later-output part of the set
+ // For now, we mark such timelocked outputs as non-aggregable, though we might introduce
+ // smarter aggregable strategy in the future.
+ aggregable: bool,
+ // Cache of package feerate committed at previous (re)broadcast. If bumping resources
+ // (either claimed output value or external utxo), it will keep increasing until holder
+ // or counterparty successful claim.
+ feerate_previous: u64,
+ // Cache of next height at which fee-bumping and rebroadcast will be attempted. In
+ // the future, we might abstract it to an observed mempool fluctuation.
+ height_timer: Option<u32>,
+ // Confirmation height of the claimed outputs set transaction. In case of reorg reaching
+ // it, we wipe out and forget the package.
+ height_original: u32,
+}
+
+impl PackageTemplate {
+ pub(crate) fn is_malleable(&self) -> bool {
+ self.malleability == PackageMalleability::Malleable
+ }
+ pub(crate) fn timelock(&self) -> u32 {
+ self.soonest_conf_deadline
+ }
+ pub(crate) fn aggregable(&self) -> bool {
+ self.aggregable
+ }
+ pub(crate) fn feerate(&self) -> u64 {
+ self.feerate_previous
+ }
+ pub(crate) fn set_feerate(&mut self, new_feerate: u64) {
+ self.feerate_previous = new_feerate;
+ }
+ pub(crate) fn timer(&self) -> Option<u32> {
+ if let Some(ref timer) = self.height_timer {
+ return Some(*timer);
+ }
+ None
+ }
+ pub(crate) fn set_timer(&mut self, new_timer: Option<u32>) {
+ self.height_timer = new_timer;
+ }
+ pub(crate) fn outpoints(&self) -> Vec<&BitcoinOutPoint> {
+ self.inputs.iter().map(|(o, _)| o).collect()
+ }
+ pub(crate) fn split_package(&mut self, split_outp: &BitcoinOutPoint) -> Option<PackageTemplate> {
+ match self.malleability {
+ PackageMalleability::Malleable => {
+ let mut split_package = None;
+ let timelock = self.soonest_conf_deadline;
+ let aggregable = self.aggregable;
+ let feerate_previous = self.feerate_previous;
+ let height_timer = self.height_timer;
+ let height_original = self.height_original;
+ self.inputs.retain(|outp| {
+ if *split_outp == outp.0 {
+ split_package = Some(PackageTemplate {
+ inputs: vec![(outp.0, outp.1.clone())],
+ malleability: PackageMalleability::Malleable,
+ soonest_conf_deadline: timelock,
+ aggregable,
+ feerate_previous,
+ height_timer,
+ height_original,
+ });
+ return false;
+ }
+ return true;
+ });
+ return split_package;
+ },
+ _ => {
+ // Note, we may try to split on remote transaction for
+ // which we don't have a competing one (HTLC-Success before
+ // timelock expiration). This explain we don't panic!
+ // We should refactor OnchainTxHandler::block_connected to
+ // only test equality on competing claims.
+ return None;
+ }
+ }
+ }
+ pub(crate) fn merge_package(&mut self, mut merge_from: PackageTemplate) {
+ assert_eq!(self.height_original, merge_from.height_original);
+ if self.malleability == PackageMalleability::Untractable || merge_from.malleability == PackageMalleability::Untractable {
+ panic!("Merging template on untractable packages");
+ }
+ if !self.aggregable || !merge_from.aggregable {
+ panic!("Merging non aggregatable packages");
+ }
+ if let Some((_, lead_input)) = self.inputs.first() {
+ for (_, v) in merge_from.inputs.iter() {
+ if !lead_input.is_compatible(v) { panic!("Merging outputs from differing types !"); }
+ }
+ } else { panic!("Merging template on an empty package"); }
+ for (k, v) in merge_from.inputs.drain(..) {
+ self.inputs.push((k, v));
+ }
+ //TODO: verify coverage and sanity?
+ if self.soonest_conf_deadline > merge_from.soonest_conf_deadline {
+ self.soonest_conf_deadline = merge_from.soonest_conf_deadline;
+ }
+ if self.feerate_previous > merge_from.feerate_previous {
+ self.feerate_previous = merge_from.feerate_previous;
+ }
+ self.height_timer = cmp::min(self.height_timer, merge_from.height_timer);
+ }
+ pub(crate) fn package_amount(&self) -> u64 {
+ let mut amounts = 0;
+ for (_, outp) in self.inputs.iter() {
+ amounts += outp.amount();
+ }
+ amounts
+ }
+ pub(crate) fn package_weight(&self, destination_script: &Script) -> usize {
+ let mut inputs_weight = 0;
+ let mut witnesses_weight = 2; // count segwit flags
+ for (_, outp) in self.inputs.iter() {
+ // previous_out_point: 36 bytes ; var_int: 1 byte ; sequence: 4 bytes
+ inputs_weight += 41 * WITNESS_SCALE_FACTOR;
+ witnesses_weight += outp.weight();
+ }
+ // version: 4 bytes ; count_tx_in: 1 byte ; count_tx_out: 1 byte ; lock_time: 4 bytes
+ let transaction_weight = 10 * WITNESS_SCALE_FACTOR;
+ // value: 8 bytes ; var_int: 1 byte ; pk_script: `destination_script.len()`
+ let output_weight = (8 + 1 + destination_script.len()) * WITNESS_SCALE_FACTOR;
+ inputs_weight + witnesses_weight + transaction_weight + output_weight
+ }
+ pub(crate) fn finalize_package<L: Deref, Signer: Sign>(&self, onchain_handler: &mut OnchainTxHandler<Signer>, value: u64, destination_script: Script, logger: &L) -> Option<Transaction>
+ where L::Target: Logger,
+ {
+ match self.malleability {
+ PackageMalleability::Malleable => {
+ let mut bumped_tx = Transaction {
+ version: 2,
+ lock_time: 0,
+ input: vec![],
+ output: vec![TxOut {
+ script_pubkey: destination_script,
+ value,
+ }],
+ };
+ for (outpoint, _) in self.inputs.iter() {
+ bumped_tx.input.push(TxIn {
+ previous_output: *outpoint,
+ script_sig: Script::new(),
+ sequence: 0xfffffffd,
+ witness: Vec::new(),
+ });
+ }
+ for (i, (outpoint, out)) in self.inputs.iter().enumerate() {
+ log_trace!(logger, "Adding claiming input for outpoint {}:{}", outpoint.txid, outpoint.vout);
+ if !out.finalize_input(&mut bumped_tx, i, onchain_handler) { return None; }
+ }
+ log_trace!(logger, "Finalized transaction {} ready to broadcast", bumped_tx.txid());
+ return Some(bumped_tx);
+ },
+ PackageMalleability::Untractable => {
+ if let Some((outpoint, outp)) = self.inputs.first() {
+ if let Some(final_tx) = outp.get_finalized_tx(outpoint, onchain_handler) {
+ log_trace!(logger, "Adding claiming input for outpoint {}:{}", outpoint.txid, outpoint.vout);
+ log_trace!(logger, "Finalized transaction {} ready to broadcast", final_tx.txid());
+ return Some(final_tx);
+ }
+ return None;
+ } else { panic!("API Error: Package must not be inputs empty"); }
+ },
+ }
+ }
+ pub (crate) fn build_package(txid: Txid, vout: u32, input_solving_data: PackageSolvingData, soonest_conf_deadline: u32, aggregable: bool, height_original: u32) -> Self {
+ let malleability = match input_solving_data {
+ PackageSolvingData::RevokedOutput(..) => { PackageMalleability::Malleable },
+ PackageSolvingData::RevokedHTLCOutput(..) => { PackageMalleability::Malleable },
+ PackageSolvingData::CounterpartyOfferedHTLCOutput(..) => { PackageMalleability::Malleable },
+ PackageSolvingData::CounterpartyReceivedHTLCOutput(..) => { PackageMalleability::Malleable },
+ PackageSolvingData::HolderHTLCOutput(..) => { PackageMalleability::Untractable },
+ PackageSolvingData::HolderFundingOutput(..) => { PackageMalleability::Untractable },
+ };
+ let mut inputs = Vec::with_capacity(1);
+ inputs.push((BitcoinOutPoint { txid, vout }, input_solving_data));
+ PackageTemplate {
+ inputs,
+ malleability,
+ soonest_conf_deadline,
+ aggregable,
+ feerate_previous: 0,
+ height_timer: None,
+ height_original,
+ }
+ }
+}
+
+impl Writeable for PackageTemplate {
+ fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
+ writer.write_all(&byte_utils::be64_to_array(self.inputs.len() as u64))?;
+ for (ref outpoint, ref rev_outp) in self.inputs.iter() {
+ outpoint.write(writer)?;
+ rev_outp.write(writer)?;
+ }
+ self.soonest_conf_deadline.write(writer)?;
+ self.feerate_previous.write(writer)?;
+ self.height_timer.write(writer)?;
+ self.height_original.write(writer)?;
+ Ok(())
+ }
+}
+
+impl Readable for PackageTemplate {
+ fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
+ let inputs_count = <u64 as Readable>::read(reader)?;
+ let mut inputs: Vec<(BitcoinOutPoint, PackageSolvingData)> = Vec::with_capacity(cmp::min(inputs_count as usize, MAX_ALLOC_SIZE / 128));
+ for _ in 0..inputs_count {
+ let outpoint = Readable::read(reader)?;
+ let rev_outp = Readable::read(reader)?;
+ inputs.push((outpoint, rev_outp));
+ }
+ let (malleability, aggregable) = if let Some((_, lead_input)) = inputs.first() {
+ match lead_input {
+ PackageSolvingData::RevokedOutput(..) => { (PackageMalleability::Malleable, true) },
+ PackageSolvingData::RevokedHTLCOutput(..) => { (PackageMalleability::Malleable, true) },
+ PackageSolvingData::CounterpartyOfferedHTLCOutput(..) => { (PackageMalleability::Malleable, true) },
+ PackageSolvingData::CounterpartyReceivedHTLCOutput(..) => { (PackageMalleability::Malleable, false) },
+ PackageSolvingData::HolderHTLCOutput(..) => { (PackageMalleability::Untractable, false) },
+ PackageSolvingData::HolderFundingOutput(..) => { (PackageMalleability::Untractable, false) },
+ }
+ } else { return Err(DecodeError::InvalidValue); };
+ let soonest_conf_deadline = Readable::read(reader)?;
+ let feerate_previous = Readable::read(reader)?;
+ let height_timer = Readable::read(reader)?;
+ let height_original = Readable::read(reader)?;
+ Ok(PackageTemplate {
+ inputs,
+ malleability,
+ soonest_conf_deadline,
+ aggregable,
+ feerate_previous,
+ height_timer,
+ height_original,
+ })
+ }
+}
+
+/// Utilities for computing witnesses weight and feerate computation for onchain operation
#[derive(PartialEq, Clone, Copy)]
pub(crate) enum InputDescriptors {
RevokedOfferedHTLC,
projects / rust-lightning / commitdiff