use bitcoin::consensus::Encodable;
use bitcoin::policy::MAX_STANDARD_TX_WEIGHT;
use bitcoin::{
- absolute::LockTime as AbsoluteLockTime, OutPoint, ScriptBuf, Sequence, Transaction, TxIn, TxOut,
+ absolute::LockTime as AbsoluteLockTime, OutPoint, ScriptBuf, Sequence, Transaction, TxIn,
+ TxOut, Weight,
};
use crate::chain::chaininterface::fee_for_weight;
}
#[derive(Debug, Clone, PartialEq)]
-pub enum AbortReason {
+pub(crate) enum AbortReason {
InvalidStateTransition,
UnexpectedCounterpartyMessage,
ReceivedTooManyTxAddInputs,
InvalidTx,
}
-#[derive(Debug)]
-pub struct TxInputWithPrevOutput {
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub(crate) struct InteractiveTxInput {
+ serial_id: SerialId,
input: TxIn,
prev_output: TxOut,
}
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub(crate) struct InteractiveTxOutput {
+ serial_id: SerialId,
+ tx_out: TxOut,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub(crate) struct ConstructedTransaction {
+ holder_is_initiator: bool,
+
+ inputs: Vec<InteractiveTxInput>,
+ outputs: Vec<InteractiveTxOutput>,
+
+ local_inputs_value_satoshis: u64,
+ local_outputs_value_satoshis: u64,
+
+ remote_inputs_value_satoshis: u64,
+ remote_outputs_value_satoshis: u64,
+
+ lock_time: AbsoluteLockTime,
+}
+
+impl ConstructedTransaction {
+ fn new(context: NegotiationContext) -> Self {
+ let local_inputs_value_satoshis = context
+ .inputs
+ .iter()
+ .filter(|(serial_id, _)| {
+ !is_serial_id_valid_for_counterparty(context.holder_is_initiator, serial_id)
+ })
+ .fold(0u64, |value, (_, input)| value.saturating_add(input.prev_output.value));
+
+ let local_outputs_value_satoshis = context
+ .outputs
+ .iter()
+ .filter(|(serial_id, _)| {
+ !is_serial_id_valid_for_counterparty(context.holder_is_initiator, serial_id)
+ })
+ .fold(0u64, |value, (_, output)| value.saturating_add(output.tx_out.value));
+
+ Self {
+ holder_is_initiator: context.holder_is_initiator,
+
+ local_inputs_value_satoshis,
+ local_outputs_value_satoshis,
+
+ remote_inputs_value_satoshis: context.remote_inputs_value(),
+ remote_outputs_value_satoshis: context.remote_outputs_value(),
+
+ inputs: context.inputs.into_values().collect(),
+ outputs: context.outputs.into_values().collect(),
+
+ lock_time: context.tx_locktime,
+ }
+ }
+
+ pub fn weight(&self) -> Weight {
+ let inputs_weight = self.inputs.iter().fold(
+ Weight::from_wu(0),
+ |weight, InteractiveTxInput { prev_output, .. }| {
+ weight.checked_add(estimate_input_weight(prev_output)).unwrap_or(Weight::MAX)
+ },
+ );
+ let outputs_weight = self.outputs.iter().fold(
+ Weight::from_wu(0),
+ |weight, InteractiveTxOutput { tx_out, .. }| {
+ weight.checked_add(get_output_weight(&tx_out.script_pubkey)).unwrap_or(Weight::MAX)
+ },
+ );
+ Weight::from_wu(TX_COMMON_FIELDS_WEIGHT)
+ .checked_add(inputs_weight)
+ .and_then(|weight| weight.checked_add(outputs_weight))
+ .unwrap_or(Weight::MAX)
+ }
+
+ pub fn into_unsigned_tx(self) -> Transaction {
+ // Inputs and outputs must be sorted by serial_id
+ let ConstructedTransaction { mut inputs, mut outputs, .. } = self;
+
+ inputs.sort_unstable_by_key(|InteractiveTxInput { serial_id, .. }| *serial_id);
+ outputs.sort_unstable_by_key(|InteractiveTxOutput { serial_id, .. }| *serial_id);
+
+ let input: Vec<TxIn> =
+ inputs.into_iter().map(|InteractiveTxInput { input, .. }| input).collect();
+ let output: Vec<TxOut> =
+ outputs.into_iter().map(|InteractiveTxOutput { tx_out, .. }| tx_out).collect();
+
+ Transaction { version: 2, lock_time: self.lock_time, input, output }
+ }
+}
+
#[derive(Debug)]
struct NegotiationContext {
holder_is_initiator: bool,
received_tx_add_input_count: u16,
received_tx_add_output_count: u16,
- inputs: HashMap<SerialId, TxInputWithPrevOutput>,
+ inputs: HashMap<SerialId, InteractiveTxInput>,
prevtx_outpoints: HashSet<OutPoint>,
- outputs: HashMap<SerialId, TxOut>,
+ outputs: HashMap<SerialId, InteractiveTxOutput>,
tx_locktime: AbsoluteLockTime,
feerate_sat_per_kw: u32,
}
-pub(crate) fn get_output_weight(script_pubkey: &ScriptBuf) -> u64 {
- (8 /* value */ + script_pubkey.consensus_encode(&mut sink()).unwrap() as u64)
- * WITNESS_SCALE_FACTOR as u64
+pub(crate) fn estimate_input_weight(prev_output: &TxOut) -> Weight {
+ Weight::from_wu(if prev_output.script_pubkey.is_v0_p2wpkh() {
+ P2WPKH_INPUT_WEIGHT_LOWER_BOUND
+ } else if prev_output.script_pubkey.is_v0_p2wsh() {
+ P2WSH_INPUT_WEIGHT_LOWER_BOUND
+ } else if prev_output.script_pubkey.is_v1_p2tr() {
+ P2TR_INPUT_WEIGHT_LOWER_BOUND
+ } else {
+ UNKNOWN_SEGWIT_VERSION_INPUT_WEIGHT_LOWER_BOUND
+ })
+}
+
+pub(crate) fn get_output_weight(script_pubkey: &ScriptBuf) -> Weight {
+ Weight::from_wu(
+ (8 /* value */ + script_pubkey.consensus_encode(&mut sink()).unwrap() as u64)
+ * WITNESS_SCALE_FACTOR as u64,
+ )
+}
+
+fn is_serial_id_valid_for_counterparty(holder_is_initiator: bool, serial_id: &SerialId) -> bool {
+ // A received `SerialId`'s parity must match the role of the counterparty.
+ holder_is_initiator == serial_id.is_for_non_initiator()
}
impl NegotiationContext {
fn is_serial_id_valid_for_counterparty(&self, serial_id: &SerialId) -> bool {
- // A received `SerialId`'s parity must match the role of the counterparty.
- self.holder_is_initiator == serial_id.is_for_non_initiator()
- }
-
- fn total_input_and_output_count(&self) -> usize {
- self.inputs.len().saturating_add(self.outputs.len())
+ is_serial_id_valid_for_counterparty(self.holder_is_initiator, serial_id)
}
- fn counterparty_inputs_contributed(
- &self,
- ) -> impl Iterator<Item = &TxInputWithPrevOutput> + Clone {
+ fn remote_inputs_value(&self) -> u64 {
self.inputs
.iter()
- .filter(move |(serial_id, _)| self.is_serial_id_valid_for_counterparty(serial_id))
- .map(|(_, input_with_prevout)| input_with_prevout)
+ .filter(|(serial_id, _)| self.is_serial_id_valid_for_counterparty(serial_id))
+ .fold(0u64, |acc, (_, InteractiveTxInput { prev_output, .. })| {
+ acc.saturating_add(prev_output.value)
+ })
}
- fn counterparty_outputs_contributed(&self) -> impl Iterator<Item = &TxOut> + Clone {
+ fn remote_outputs_value(&self) -> u64 {
self.outputs
.iter()
- .filter(move |(serial_id, _)| self.is_serial_id_valid_for_counterparty(serial_id))
- .map(|(_, output)| output)
+ .filter(|(serial_id, _)| self.is_serial_id_valid_for_counterparty(serial_id))
+ .fold(0u64, |acc, (_, InteractiveTxOutput { tx_out, .. })| {
+ acc.saturating_add(tx_out.value)
+ })
+ }
+
+ fn remote_inputs_weight(&self) -> Weight {
+ Weight::from_wu(
+ self.inputs
+ .iter()
+ .filter(|(serial_id, _)| self.is_serial_id_valid_for_counterparty(serial_id))
+ .fold(0u64, |weight, (_, InteractiveTxInput { prev_output, .. })| {
+ weight.saturating_add(estimate_input_weight(prev_output).to_wu())
+ }),
+ )
+ }
+
+ fn remote_outputs_weight(&self) -> Weight {
+ Weight::from_wu(
+ self.outputs
+ .iter()
+ .filter(|(serial_id, _)| self.is_serial_id_valid_for_counterparty(serial_id))
+ .fold(0u64, |weight, (_, InteractiveTxOutput { tx_out, .. })| {
+ weight.saturating_add(get_output_weight(&tx_out.script_pubkey).to_wu())
+ }),
+ )
}
fn received_tx_add_input(&mut self, msg: &msgs::TxAddInput) -> Result<(), AbortReason> {
},
hash_map::Entry::Vacant(entry) => {
let prev_outpoint = OutPoint { txid, vout: msg.prevtx_out };
- entry.insert(TxInputWithPrevOutput {
+ entry.insert(InteractiveTxInput {
+ serial_id: msg.serial_id,
input: TxIn {
previous_output: prev_outpoint,
sequence: Sequence(msg.sequence),
// bitcoin supply.
let mut outputs_value: u64 = 0;
for output in self.outputs.iter() {
- outputs_value = outputs_value.saturating_add(output.1.value);
+ outputs_value = outputs_value.saturating_add(output.1.tx_out.value);
}
if outputs_value.saturating_add(msg.sats) > TOTAL_BITCOIN_SUPPLY_SATOSHIS {
// The receiving node:
Err(AbortReason::DuplicateSerialId)
},
hash_map::Entry::Vacant(entry) => {
- entry.insert(TxOut { value: msg.sats, script_pubkey: msg.script.clone() });
+ entry.insert(InteractiveTxOutput {
+ serial_id: msg.serial_id,
+ tx_out: TxOut { value: msg.sats, script_pubkey: msg.script.clone() },
+ });
Ok(())
},
}
// We have added an input that already exists
return Err(AbortReason::PrevTxOutInvalid);
}
- self.inputs.insert(msg.serial_id, TxInputWithPrevOutput { input, prev_output });
+ self.inputs.insert(
+ msg.serial_id,
+ InteractiveTxInput { serial_id: msg.serial_id, input, prev_output },
+ );
Ok(())
}
fn sent_tx_add_output(&mut self, msg: &msgs::TxAddOutput) -> Result<(), AbortReason> {
- self.outputs
- .insert(msg.serial_id, TxOut { value: msg.sats, script_pubkey: msg.script.clone() });
+ self.outputs.insert(
+ msg.serial_id,
+ InteractiveTxOutput {
+ serial_id: msg.serial_id,
+ tx_out: TxOut { value: msg.sats, script_pubkey: msg.script.clone() },
+ },
+ );
Ok(())
}
}
fn check_counterparty_fees(
- &self, counterparty_inputs_value: u64, counterparty_outputs_value: u64,
+ &self, counterparty_fees_contributed: u64,
) -> Result<(), AbortReason> {
- let mut counterparty_weight_contributed: u64 = self
- .counterparty_outputs_contributed()
- .map(|output| get_output_weight(&output.script_pubkey))
- .sum();
- // We don't know the counterparty's witnesses ahead of time obviously, so we use the lower bounds
- // specified in BOLT 3.
- let mut total_inputs_weight: u64 = 0;
- for TxInputWithPrevOutput { prev_output, .. } in self.counterparty_inputs_contributed() {
- total_inputs_weight =
- total_inputs_weight.saturating_add(if prev_output.script_pubkey.is_v0_p2wpkh() {
- P2WPKH_INPUT_WEIGHT_LOWER_BOUND
- } else if prev_output.script_pubkey.is_v0_p2wsh() {
- P2WSH_INPUT_WEIGHT_LOWER_BOUND
- } else if prev_output.script_pubkey.is_v1_p2tr() {
- P2TR_INPUT_WEIGHT_LOWER_BOUND
- } else {
- UNKNOWN_SEGWIT_VERSION_INPUT_WEIGHT_LOWER_BOUND
- });
- }
- counterparty_weight_contributed =
- counterparty_weight_contributed.saturating_add(total_inputs_weight);
- let counterparty_fees_contributed =
- counterparty_inputs_value.saturating_sub(counterparty_outputs_value);
+ let counterparty_weight_contributed = self
+ .remote_inputs_weight()
+ .to_wu()
+ .saturating_add(self.remote_outputs_weight().to_wu());
let mut required_counterparty_contribution_fee =
fee_for_weight(self.feerate_sat_per_kw, counterparty_weight_contributed);
if !self.holder_is_initiator {
Ok(())
}
- fn build_transaction(self) -> Result<Transaction, AbortReason> {
+ fn validate_tx(self) -> Result<ConstructedTransaction, AbortReason> {
// The receiving node:
// MUST fail the negotiation if:
// - the peer's total input satoshis is less than their outputs
- let mut counterparty_inputs_value: u64 = 0;
- let mut counterparty_outputs_value: u64 = 0;
- for input in self.counterparty_inputs_contributed() {
- counterparty_inputs_value =
- counterparty_inputs_value.saturating_add(input.prev_output.value);
- }
- for output in self.counterparty_outputs_contributed() {
- counterparty_outputs_value = counterparty_outputs_value.saturating_add(output.value);
- }
- if counterparty_inputs_value < counterparty_outputs_value {
+ let remote_inputs_value = self.remote_inputs_value();
+ let remote_outputs_value = self.remote_outputs_value();
+ if remote_inputs_value < remote_outputs_value {
return Err(AbortReason::OutputsValueExceedsInputsValue);
}
}
// - the peer's paid feerate does not meet or exceed the agreed feerate (based on the minimum fee).
- self.check_counterparty_fees(counterparty_inputs_value, counterparty_outputs_value)?;
+ self.check_counterparty_fees(remote_inputs_value.saturating_sub(remote_outputs_value))?;
- // Inputs and outputs must be sorted by serial_id
- let mut inputs = self.inputs.into_iter().collect::<Vec<_>>();
- let mut outputs = self.outputs.into_iter().collect::<Vec<_>>();
- inputs.sort_unstable_by_key(|(serial_id, _)| *serial_id);
- outputs.sort_unstable_by_key(|(serial_id, _)| *serial_id);
+ let constructed_tx = ConstructedTransaction::new(self);
- let tx_to_validate = Transaction {
- version: 2,
- lock_time: self.tx_locktime,
- input: inputs.into_iter().map(|(_, input)| input.input).collect(),
- output: outputs.into_iter().map(|(_, output)| output).collect(),
- };
- if tx_to_validate.weight().to_wu() > MAX_STANDARD_TX_WEIGHT as u64 {
+ if constructed_tx.weight().to_wu() > MAX_STANDARD_TX_WEIGHT as u64 {
return Err(AbortReason::TransactionTooLarge);
}
- Ok(tx_to_validate)
+ Ok(constructed_tx)
}
}
ReceivedTxComplete,
"We have received a `tx_complete` message and the counterparty is awaiting ours."
);
-define_state!(NegotiationComplete, Transaction, "We have exchanged consecutive `tx_complete` messages with the counterparty and the transaction negotiation is complete.");
+define_state!(NegotiationComplete, ConstructedTransaction, "We have exchanged consecutive `tx_complete` messages with the counterparty and the transaction negotiation is complete.");
define_state!(
NegotiationAborted,
AbortReason,
impl StateTransition<NegotiationComplete, &msgs::TxComplete> for $tx_complete_state {
fn transition(self, _data: &msgs::TxComplete) -> StateTransitionResult<NegotiationComplete> {
let context = self.into_negotiation_context();
- let tx = context.build_transaction()?;
+ let tx = context.validate_tx()?;
Ok(NegotiationComplete(tx))
}
}
]);
}
-pub struct InteractiveTxConstructor {
+pub(crate) struct InteractiveTxConstructor {
state_machine: StateMachine,
channel_id: ChannelId,
inputs_to_contribute: Vec<(SerialId, TxIn, TransactionU16LenLimited)>,
outputs_to_contribute: Vec<(SerialId, TxOut)>,
}
-pub enum InteractiveTxMessageSend {
+pub(crate) enum InteractiveTxMessageSend {
TxAddInput(msgs::TxAddInput),
TxAddOutput(msgs::TxAddOutput),
TxComplete(msgs::TxComplete),
serial_id
}
-pub enum HandleTxCompleteValue {
+pub(crate) enum HandleTxCompleteValue {
SendTxMessage(InteractiveTxMessageSend),
- SendTxComplete(InteractiveTxMessageSend, Transaction),
- NegotiationComplete(Transaction),
+ SendTxComplete(InteractiveTxMessageSend, ConstructedTransaction),
+ NegotiationComplete(ConstructedTransaction),
}
impl InteractiveTxConstructor {
}
assert!(message_send_a.is_none());
assert!(message_send_b.is_none());
- assert_eq!(final_tx_a, final_tx_b);
+ assert_eq!(final_tx_a.unwrap().into_unsigned_tx(), final_tx_b.unwrap().into_unsigned_tx());
assert!(session.expect_error.is_none(), "Test: {}", session.description);
}
let p2wpkh_fee = fee_for_weight(TEST_FEERATE_SATS_PER_KW, P2WPKH_INPUT_WEIGHT_LOWER_BOUND);
let outputs_fee = fee_for_weight(
TEST_FEERATE_SATS_PER_KW,
- get_output_weight(&generate_p2wpkh_script_pubkey()),
+ get_output_weight(&generate_p2wpkh_script_pubkey()).to_wu(),
);
let tx_common_fields_fee =
fee_for_weight(TEST_FEERATE_SATS_PER_KW, TX_COMMON_FIELDS_WEIGHT);