use alloc::collections::BTreeMap;
use core::ops::Deref;
-use crate::chain::chaininterface::{BroadcasterInterface, compute_feerate_sat_per_1000_weight, fee_for_weight, FEERATE_FLOOR_SATS_PER_KW};
+use crate::chain::chaininterface::{BroadcasterInterface, fee_for_weight};
use crate::chain::ClaimId;
use crate::io_extras::sink;
use crate::ln::channel::ANCHOR_OUTPUT_VALUE_SATOSHI;
use crate::ln::chan_utils;
use crate::ln::chan_utils::{
ANCHOR_INPUT_WITNESS_WEIGHT, HTLC_SUCCESS_INPUT_ANCHOR_WITNESS_WEIGHT,
- HTLC_TIMEOUT_INPUT_ANCHOR_WITNESS_WEIGHT, ChannelTransactionParameters, HTLCOutputInCommitment
+ HTLC_TIMEOUT_INPUT_ANCHOR_WITNESS_WEIGHT, HTLCOutputInCommitment
};
-use crate::ln::features::ChannelTypeFeatures;
-use crate::ln::PaymentPreimage;
use crate::prelude::*;
-use crate::sign::{ChannelSigner, EcdsaChannelSigner, SignerProvider, WriteableEcdsaChannelSigner};
+use crate::sign::{
+ ChannelDerivationParameters, HTLCDescriptor, EcdsaChannelSigner, SignerProvider,
+ WriteableEcdsaChannelSigner, P2WPKH_WITNESS_WEIGHT
+};
use crate::sync::Mutex;
use crate::util::logger::Logger;
-use bitcoin::{OutPoint, PackedLockTime, PubkeyHash, Sequence, Script, Transaction, Txid, TxIn, TxOut, Witness, WPubkeyHash};
+use bitcoin::{OutPoint, PackedLockTime, PubkeyHash, Sequence, Script, Transaction, TxIn, TxOut, Witness, WPubkeyHash};
use bitcoin::blockdata::constants::WITNESS_SCALE_FACTOR;
use bitcoin::consensus::Encodable;
use bitcoin::secp256k1;
-use bitcoin::secp256k1::{PublicKey, Secp256k1};
+use bitcoin::secp256k1::Secp256k1;
use bitcoin::secp256k1::ecdsa::Signature;
const EMPTY_SCRIPT_SIG_WEIGHT: u64 = 1 /* empty script_sig */ * WITNESS_SCALE_FACTOR as u64;
const BASE_INPUT_WEIGHT: u64 = BASE_INPUT_SIZE * WITNESS_SCALE_FACTOR as u64;
-/// The parameters required to derive a channel signer via [`SignerProvider`].
-#[derive(Clone, Debug, PartialEq, Eq)]
-pub struct ChannelDerivationParameters {
- /// The value in satoshis of the channel we're attempting to spend the anchor output of.
- pub value_satoshis: u64,
- /// The unique identifier to re-derive the signer for the associated channel.
- pub keys_id: [u8; 32],
- /// The necessary channel parameters that need to be provided to the re-derived signer through
- /// [`ChannelSigner::provide_channel_parameters`].
- ///
- /// [`ChannelSigner::provide_channel_parameters`]: crate::sign::ChannelSigner::provide_channel_parameters
- pub transaction_parameters: ChannelTransactionParameters,
-}
-
/// A descriptor used to sign for a commitment transaction's anchor output.
#[derive(Clone, Debug, PartialEq, Eq)]
pub struct AnchorDescriptor {
}
}
-/// A descriptor used to sign for a commitment transaction's HTLC output.
-#[derive(Clone, Debug, PartialEq, Eq)]
-pub struct HTLCDescriptor {
- /// The parameters required to derive the signer for the HTLC input.
- pub channel_derivation_parameters: ChannelDerivationParameters,
- /// The txid of the commitment transaction in which the HTLC output lives.
- pub commitment_txid: Txid,
- /// The number of the commitment transaction in which the HTLC output lives.
- pub per_commitment_number: u64,
- /// The key tweak corresponding to the number of the commitment transaction in which the HTLC
- /// output lives. This tweak is applied to all the basepoints for both parties in the channel to
- /// arrive at unique keys per commitment.
- ///
- /// See <https://github.com/lightning/bolts/blob/master/03-transactions.md#keys> for more info.
- pub per_commitment_point: PublicKey,
- /// The details of the HTLC as it appears in the commitment transaction.
- pub htlc: HTLCOutputInCommitment,
- /// The preimage, if `Some`, to claim the HTLC output with. If `None`, the timeout path must be
- /// taken.
- pub preimage: Option<PaymentPreimage>,
- /// The counterparty's signature required to spend the HTLC output.
- pub counterparty_sig: Signature
-}
-
-impl HTLCDescriptor {
- /// Returns the outpoint of the HTLC output in the commitment transaction. This is the outpoint
- /// being spent by the HTLC input in the HTLC transaction.
- pub fn outpoint(&self) -> OutPoint {
- OutPoint {
- txid: self.commitment_txid,
- vout: self.htlc.transaction_output_index.unwrap(),
- }
- }
-
- /// Returns the UTXO to be spent by the HTLC input, which can be obtained via
- /// [`Self::unsigned_tx_input`].
- pub fn previous_utxo<C: secp256k1::Signing + secp256k1::Verification>(&self, secp: &Secp256k1<C>) -> TxOut {
- TxOut {
- script_pubkey: self.witness_script(secp).to_v0_p2wsh(),
- value: self.htlc.amount_msat / 1000,
- }
- }
-
- /// Returns the unsigned transaction input spending the HTLC output in the commitment
- /// transaction.
- pub fn unsigned_tx_input(&self) -> TxIn {
- chan_utils::build_htlc_input(&self.commitment_txid, &self.htlc, &ChannelTypeFeatures::anchors_zero_htlc_fee_and_dependencies())
- }
-
- /// Returns the delayed output created as a result of spending the HTLC output in the commitment
- /// transaction.
- pub fn tx_output<C: secp256k1::Signing + secp256k1::Verification>(&self, secp: &Secp256k1<C>) -> TxOut {
- let channel_params = self.channel_derivation_parameters.transaction_parameters.as_holder_broadcastable();
- let broadcaster_keys = channel_params.broadcaster_pubkeys();
- let counterparty_keys = channel_params.countersignatory_pubkeys();
- let broadcaster_delayed_key = chan_utils::derive_public_key(
- secp, &self.per_commitment_point, &broadcaster_keys.delayed_payment_basepoint
- );
- let counterparty_revocation_key = chan_utils::derive_public_revocation_key(
- secp, &self.per_commitment_point, &counterparty_keys.revocation_basepoint
- );
- chan_utils::build_htlc_output(
- 0 /* feerate_per_kw */, channel_params.contest_delay(), &self.htlc,
- &ChannelTypeFeatures::anchors_zero_htlc_fee_and_dependencies(), &broadcaster_delayed_key, &counterparty_revocation_key
- )
- }
-
- /// Returns the witness script of the HTLC output in the commitment transaction.
- pub fn witness_script<C: secp256k1::Signing + secp256k1::Verification>(&self, secp: &Secp256k1<C>) -> Script {
- let channel_params = self.channel_derivation_parameters.transaction_parameters.as_holder_broadcastable();
- let broadcaster_keys = channel_params.broadcaster_pubkeys();
- let counterparty_keys = channel_params.countersignatory_pubkeys();
- let broadcaster_htlc_key = chan_utils::derive_public_key(
- secp, &self.per_commitment_point, &broadcaster_keys.htlc_basepoint
- );
- let counterparty_htlc_key = chan_utils::derive_public_key(
- secp, &self.per_commitment_point, &counterparty_keys.htlc_basepoint
- );
- let counterparty_revocation_key = chan_utils::derive_public_revocation_key(
- secp, &self.per_commitment_point, &counterparty_keys.revocation_basepoint
- );
- chan_utils::get_htlc_redeemscript_with_explicit_keys(
- &self.htlc, &ChannelTypeFeatures::anchors_zero_htlc_fee_and_dependencies(), &broadcaster_htlc_key, &counterparty_htlc_key,
- &counterparty_revocation_key,
- )
- }
-
- /// Returns the fully signed witness required to spend the HTLC output in the commitment
- /// transaction.
- pub fn tx_input_witness(&self, signature: &Signature, witness_script: &Script) -> Witness {
- chan_utils::build_htlc_input_witness(
- signature, &self.counterparty_sig, &self.preimage, witness_script, &ChannelTypeFeatures::anchors_zero_htlc_fee_and_dependencies() /* opt_anchors */
- )
- }
-
- /// Derives the channel signer required to sign the HTLC input.
- pub fn derive_channel_signer<S: WriteableEcdsaChannelSigner, SP: Deref>(&self, signer_provider: &SP) -> S
- where
- SP::Target: SignerProvider<Signer = S>
- {
- let mut signer = signer_provider.derive_channel_signer(
- self.channel_derivation_parameters.value_satoshis,
- self.channel_derivation_parameters.keys_id,
- );
- signer.provide_channel_parameters(&self.channel_derivation_parameters.transaction_parameters);
- signer
- }
-}
-
/// Represents the different types of transactions, originating from LDK, to be bumped.
#[derive(Clone, Debug, PartialEq, Eq)]
pub enum BumpTransactionEvent {
///
/// [`EcdsaChannelSigner`]: crate::sign::EcdsaChannelSigner
/// [`EcdsaChannelSigner::sign_holder_htlc_transaction`]: crate::sign::EcdsaChannelSigner::sign_holder_htlc_transaction
- /// [`HTLCDescriptor::tx_input_witness`]: HTLCDescriptor::tx_input_witness
HTLCResolution {
/// The unique identifier for the claim of the HTLCs in the confirmed commitment
/// transaction.
/// An input that must be included in a transaction when performing coin selection through
/// [`CoinSelectionSource::select_confirmed_utxos`]. It is guaranteed to be a SegWit input, so it
/// must have an empty [`TxIn::script_sig`] when spent.
+#[derive(Clone, Debug, Hash, PartialOrd, Ord, PartialEq, Eq)]
pub struct Input {
/// The unique identifier of the input.
pub outpoint: OutPoint,
/// An unspent transaction output that is available to spend resulting from a successful
/// [`CoinSelection`] attempt.
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, Hash, PartialOrd, Ord, PartialEq, Eq)]
pub struct Utxo {
/// The unique identifier of the output.
pub outpoint: OutPoint,
}
impl Utxo {
- const P2WPKH_WITNESS_WEIGHT: u64 = 1 /* num stack items */ +
- 1 /* sig length */ +
- 73 /* sig including sighash flag */ +
- 1 /* pubkey length */ +
- 33 /* pubkey */;
-
/// Returns a `Utxo` with the `satisfaction_weight` estimate for a legacy P2PKH output.
pub fn new_p2pkh(outpoint: OutPoint, value: u64, pubkey_hash: &PubkeyHash) -> Self {
let script_sig_size = 1 /* script_sig length */ +
value,
script_pubkey: Script::new_p2sh(&Script::new_v0_p2wpkh(pubkey_hash).script_hash()),
},
- satisfaction_weight: script_sig_size * WITNESS_SCALE_FACTOR as u64 + Self::P2WPKH_WITNESS_WEIGHT,
+ satisfaction_weight: script_sig_size * WITNESS_SCALE_FACTOR as u64 + P2WPKH_WITNESS_WEIGHT,
}
}
value,
script_pubkey: Script::new_v0_p2wpkh(pubkey_hash),
},
- satisfaction_weight: EMPTY_SCRIPT_SIG_WEIGHT + Self::P2WPKH_WITNESS_WEIGHT,
+ satisfaction_weight: EMPTY_SCRIPT_SIG_WEIGHT + P2WPKH_WITNESS_WEIGHT,
}
}
}
/// The result of a successful coin selection attempt for a transaction requiring additional UTXOs
/// to cover its fees.
+#[derive(Clone, Debug)]
pub struct CoinSelection {
/// The set of UTXOs (with at least 1 confirmation) to spend and use within a transaction
/// requiring additional fees.
fn select_confirmed_utxos_internal(
&self, utxos: &[Utxo], claim_id: ClaimId, force_conflicting_utxo_spend: bool,
tolerate_high_network_feerates: bool, target_feerate_sat_per_1000_weight: u32,
- preexisting_tx_weight: u64, target_amount_sat: u64,
+ preexisting_tx_weight: u64, input_amount_sat: u64, target_amount_sat: u64,
) -> Result<CoinSelection, ()> {
let mut locked_utxos = self.locked_utxos.lock().unwrap();
let mut eligible_utxos = utxos.iter().filter_map(|utxo| {
}).collect::<Vec<_>>();
eligible_utxos.sort_unstable_by_key(|(utxo, _)| utxo.output.value);
- let mut selected_amount = 0;
+ let mut selected_amount = input_amount_sat;
let mut total_fees = fee_for_weight(target_feerate_sat_per_1000_weight, preexisting_tx_weight);
let mut selected_utxos = Vec::new();
for (utxo, fee_to_spend_utxo) in eligible_utxos {
let preexisting_tx_weight = 2 /* segwit marker & flag */ + total_input_weight +
((BASE_TX_SIZE + total_output_size) * WITNESS_SCALE_FACTOR as u64);
+ let input_amount_sat: u64 = must_spend.iter().map(|input| input.previous_utxo.value).sum();
let target_amount_sat = must_pay_to.iter().map(|output| output.value).sum();
let do_coin_selection = |force_conflicting_utxo_spend: bool, tolerate_high_network_feerates: bool| {
log_debug!(self.logger, "Attempting coin selection targeting {} sat/kW (force_conflicting_utxo_spend = {}, tolerate_high_network_feerates = {})",
target_feerate_sat_per_1000_weight, force_conflicting_utxo_spend, tolerate_high_network_feerates);
self.select_confirmed_utxos_internal(
&utxos, claim_id, force_conflicting_utxo_spend, tolerate_high_network_feerates,
- target_feerate_sat_per_1000_weight, preexisting_tx_weight, target_amount_sat,
+ target_feerate_sat_per_1000_weight, preexisting_tx_weight, input_amount_sat, target_amount_sat,
)
};
do_coin_selection(false, false)
commitment_tx: &Transaction, commitment_tx_fee_sat: u64, anchor_descriptor: &AnchorDescriptor,
) -> Result<(), ()> {
// Our commitment transaction already has fees allocated to it, so we should take them into
- // account. We compute its feerate and subtract it from the package target, using the result
- // as the target feerate for our anchor transaction. Unfortunately, this results in users
- // overpaying by a small margin since we don't yet know the anchor transaction size, and
- // avoiding the small overpayment only makes our API even more complex.
- let commitment_tx_sat_per_1000_weight: u32 = compute_feerate_sat_per_1000_weight(
- commitment_tx_fee_sat, commitment_tx.weight() as u64,
- );
- let anchor_target_feerate_sat_per_1000_weight = core::cmp::max(
- package_target_feerate_sat_per_1000_weight - commitment_tx_sat_per_1000_weight,
- FEERATE_FLOOR_SATS_PER_KW,
- );
-
- log_debug!(self.logger, "Peforming coin selection for anchor transaction targeting {} sat/kW",
- anchor_target_feerate_sat_per_1000_weight);
+ // account. We do so by pretending the commitment tranasction's fee and weight are part of
+ // the anchor input.
+ let mut anchor_utxo = anchor_descriptor.previous_utxo();
+ anchor_utxo.value += commitment_tx_fee_sat;
let must_spend = vec![Input {
outpoint: anchor_descriptor.outpoint,
- previous_utxo: anchor_descriptor.previous_utxo(),
+ previous_utxo: anchor_utxo,
satisfaction_weight: commitment_tx.weight() as u64 + ANCHOR_INPUT_WITNESS_WEIGHT + EMPTY_SCRIPT_SIG_WEIGHT,
}];
+ #[cfg(debug_assertions)]
+ let must_spend_amount = must_spend.iter().map(|input| input.previous_utxo.value).sum::<u64>();
+
+ log_debug!(self.logger, "Peforming coin selection for commitment package (commitment and anchor transaction) targeting {} sat/kW",
+ package_target_feerate_sat_per_1000_weight);
let coin_selection = self.utxo_source.select_confirmed_utxos(
- claim_id, must_spend, &[], anchor_target_feerate_sat_per_1000_weight,
+ claim_id, must_spend, &[], package_target_feerate_sat_per_1000_weight,
)?;
let mut anchor_tx = Transaction {
input: vec![anchor_descriptor.unsigned_tx_input()],
output: vec![],
};
+
+ #[cfg(debug_assertions)]
+ let total_satisfaction_weight = ANCHOR_INPUT_WITNESS_WEIGHT + EMPTY_SCRIPT_SIG_WEIGHT +
+ coin_selection.confirmed_utxos.iter().map(|utxo| utxo.satisfaction_weight).sum::<u64>();
#[cfg(debug_assertions)]
- let total_satisfaction_weight =
- coin_selection.confirmed_utxos.iter().map(|utxo| utxo.satisfaction_weight).sum::<u64>() +
- ANCHOR_INPUT_WITNESS_WEIGHT + EMPTY_SCRIPT_SIG_WEIGHT;
+ let total_input_amount = must_spend_amount +
+ coin_selection.confirmed_utxos.iter().map(|utxo| utxo.output.value).sum::<u64>();
self.process_coin_selection(&mut anchor_tx, coin_selection);
let anchor_txid = anchor_tx.txid();
// never underestimate.
assert!(expected_signed_tx_weight >= signed_tx_weight &&
expected_signed_tx_weight - (expected_signed_tx_weight / 100) <= signed_tx_weight);
+
+ let expected_package_fee = fee_for_weight(package_target_feerate_sat_per_1000_weight,
+ signed_tx_weight + commitment_tx.weight() as u64);
+ let package_fee = total_input_amount -
+ anchor_tx.output.iter().map(|output| output.value).sum::<u64>();
+ // Our fee should be within a 5% error margin of the expected fee based on the
+ // feerate and transaction weight and we should never pay less than required.
+ let fee_error_margin = expected_package_fee * 5 / 100;
+ assert!(package_fee >= expected_package_fee &&
+ package_fee - fee_error_margin <= expected_package_fee);
}
log_info!(self.logger, "Broadcasting anchor transaction {} to bump channel close with txid {}",
log_debug!(self.logger, "Peforming coin selection for HTLC transaction targeting {} sat/kW",
target_feerate_sat_per_1000_weight);
+
#[cfg(debug_assertions)]
let must_spend_satisfaction_weight =
must_spend.iter().map(|input| input.satisfaction_weight).sum::<u64>();
+ #[cfg(debug_assertions)]
+ let must_spend_amount = must_spend.iter().map(|input| input.previous_utxo.value).sum::<u64>();
+
let coin_selection = self.utxo_source.select_confirmed_utxos(
claim_id, must_spend, &htlc_tx.output, target_feerate_sat_per_1000_weight,
)?;
+
+ #[cfg(debug_assertions)]
+ let total_satisfaction_weight = must_spend_satisfaction_weight +
+ coin_selection.confirmed_utxos.iter().map(|utxo| utxo.satisfaction_weight).sum::<u64>();
#[cfg(debug_assertions)]
- let total_satisfaction_weight =
- coin_selection.confirmed_utxos.iter().map(|utxo| utxo.satisfaction_weight).sum::<u64>() +
- must_spend_satisfaction_weight;
+ let total_input_amount = must_spend_amount +
+ coin_selection.confirmed_utxos.iter().map(|utxo| utxo.output.value).sum::<u64>();
+
self.process_coin_selection(&mut htlc_tx, coin_selection);
#[cfg(debug_assertions)]
// never underestimate.
assert!(expected_signed_tx_weight >= signed_tx_weight &&
expected_signed_tx_weight - (expected_signed_tx_weight / 100) <= signed_tx_weight);
+
+ let expected_signed_tx_fee = fee_for_weight(target_feerate_sat_per_1000_weight, signed_tx_weight);
+ let signed_tx_fee = total_input_amount -
+ htlc_tx.output.iter().map(|output| output.value).sum::<u64>();
+ // Our fee should be within a 5% error margin of the expected fee based on the
+ // feerate and transaction weight and we should never pay less than required.
+ let fee_error_margin = expected_signed_tx_fee * 5 / 100;
+ assert!(signed_tx_fee >= expected_signed_tx_fee &&
+ signed_tx_fee - fee_error_margin <= expected_signed_tx_fee);
}
log_info!(self.logger, "Broadcasting {}", log_tx!(htlc_tx));
projects / rust-lightning / blobdiff