f - use prev_output in SharedOwnedInput

Author: jkczyz

lightning/src/ln/interactivetxs.rs

@@ -121,12 +121,6 @@ pub(crate) enum AbortReason {
 	DuplicateFundingOutput,
 	/// More than one funding (shared) input found.
 	DuplicateFundingInput,
-	/// The intended local part of the funding output is higher than the actual shared funding output,
-	/// if funding output is provided by the peer this is an interop error,
-	/// if provided by the same node than internal input consistency error.
-	InvalidLowFundingOutputValue,
-	/// The intended local part of the funding input is higher than the actual shared funding input.
-	InvalidLowFundingInputValue,
 	/// Internal error
 	InternalError(&'static str),
 }
@@ -186,12 +180,6 @@ impl Display for AbortReason {
 				f.write_str("More than one funding output found")
 			},
 			AbortReason::DuplicateFundingInput => f.write_str("More than one funding input found"),
-			AbortReason::InvalidLowFundingOutputValue => f.write_str(
-				"Local part of funding output value is greater than the funding output value",
-			),
-			AbortReason::InvalidLowFundingInputValue => f.write_str(
-				"Local part of shared input value is greater than the shared input value",
-			),
 			AbortReason::InternalError(text) => {
 				f.write_fmt(format_args!("Internal error: {}", text))
 			},
@@ -1268,23 +1256,24 @@ struct SingleOwnedInput {
 #[derive(Clone, Debug, Eq, PartialEq)]
 pub(super) struct SharedOwnedInput {
 	input: TxIn,
-	value: u64,
+	prev_output: TxOut,
 	local_owned: u64,
 }
 
 impl SharedOwnedInput {
-	pub fn new(input: TxIn, value: u64, local_owned: u64) -> Self {
+	pub fn new(input: TxIn, prev_output: TxOut, local_owned: u64) -> Self {
+		let value = prev_output.value.to_sat();
 		debug_assert!(
 			local_owned <= value,
 			"SharedOwnedInput: Inconsistent local_owned value {}, larger than prev out value {}",
 			local_owned,
 			value,
 		);
-		Self { input, value, local_owned }
+		Self { input, prev_output, local_owned }
 	}
 
 	fn remote_owned(&self) -> u64 {
-		self.value.saturating_sub(self.local_owned)
+		self.prev_output.value.to_sat().saturating_sub(self.local_owned)
 	}
 }
 
@@ -1296,7 +1285,7 @@ enum InputOwned {
 	/// Belongs to a single party -- controlled exclusively and fully belonging to a single party
 	/// Includes the input and the previous output
 	Single(SingleOwnedInput),
-	// Input with shared control and value split between the two ends (or fully at one side)
+	/// Input with shared control and value split between the counterparties (or fully by one).
 	Shared(SharedOwnedInput),
 }
 
@@ -1325,7 +1314,7 @@ impl InputOwned {
 	pub fn value(&self) -> u64 {
 		match self {
 			InputOwned::Single(single) => single.prev_output.value.to_sat(),
-			InputOwned::Shared(shared) => shared.value,
+			InputOwned::Shared(shared) => shared.prev_output.value.to_sat(),
 		}
 	}
 
@@ -1359,7 +1348,7 @@ impl InputOwned {
 	fn estimate_input_weight(&self) -> Weight {
 		match self {
 			InputOwned::Single(single) => estimate_input_weight(&single.prev_output),
-			InputOwned::Shared(_shared) => Weight::from_wu(P2WSH_INPUT_WEIGHT_LOWER_BOUND),
+			InputOwned::Shared(shared) => estimate_input_weight(&shared.prev_output),
 		}
 	}
 }
@@ -1728,10 +1717,6 @@ impl InteractiveTxConstructor {
 			if is_initiator {
 				// Add shared funding input
 				let serial_id = generate_holder_serial_id(entropy_source, is_initiator);
-				// Sanity check
-				if shared_funding_input.local_owned > shared_funding_input.value {
-					return Err(AbortReason::InvalidLowFundingInputValue);
-				}
 				inputs_to_contribute
 					.push((serial_id, InputOwned::Shared(shared_funding_input.clone())));
 			}
@@ -2046,12 +2031,12 @@ mod tests {
 	struct TestSession {
 		description: &'static str,
 		inputs_a: Vec<(TxIn, TransactionU16LenLimited)>,
-		a_shared_input: Option<(OutPoint, u64, u64)>,
+		a_shared_input: Option<(OutPoint, TxOut, u64)>,
 		/// The funding output, with the value contributed
 		shared_output_a: (TxOut, u64),
 		outputs_a: Vec<TxOut>,
 		inputs_b: Vec<(TxIn, TransactionU16LenLimited)>,
-		b_shared_input: Option<(OutPoint, u64, u64)>,
+		b_shared_input: Option<(OutPoint, TxOut, u64)>,
 		/// The funding output, with the value contributed
 		shared_output_b: (TxOut, u64),
 		outputs_b: Vec<TxOut>,
@@ -2096,14 +2081,14 @@ mod tests {
 			is_initiator: true,
 			funding_tx_locktime,
 			inputs_to_contribute: session.inputs_a,
-			shared_funding_input: session.a_shared_input.map(|(op, val, lo)| {
+			shared_funding_input: session.a_shared_input.map(|(op, prev_output, lo)| {
 				SharedOwnedInput::new(
 					TxIn {
 						previous_output: op,
 						sequence: Sequence::ENABLE_RBF_NO_LOCKTIME,
 						..Default::default()
 					},
-					val,
+					prev_output,
 					lo,
 				)
 			}),
@@ -2133,14 +2118,14 @@ mod tests {
 			is_initiator: false,
 			funding_tx_locktime,
 			inputs_to_contribute: session.inputs_b,
-			shared_funding_input: session.b_shared_input.map(|(op, val, lo)| {
+			shared_funding_input: session.b_shared_input.map(|(op, prev_output, lo)| {
 				SharedOwnedInput::new(
 					TxIn {
 						previous_output: op,
 						sequence: Sequence::ENABLE_RBF_NO_LOCKTIME,
 						..Default::default()
 					},
-					val,
+					prev_output,
 					lo,
 				)
 			}),
@@ -2319,16 +2304,17 @@ mod tests {
 
 	fn generate_shared_input(
 		prev_funding_tx: &Transaction, vout: u32, local_owned: u64,
-	) -> (OutPoint, u64, u64) {
+	) -> (OutPoint, TxOut, u64) {
 		let txid = prev_funding_tx.compute_txid();
-		let value = prev_funding_tx.output.get(vout as usize).unwrap().value.to_sat();
+		let prev_output = prev_funding_tx.output.get(vout as usize).unwrap();
+		let value = prev_output.value.to_sat();
 		assert!(
 			local_owned <= value,
 			"local owned > value for shared input, {} {}",
 			local_owned,
 			value,
 		);
-		(OutPoint { txid, vout }, value, local_owned)
+		(OutPoint { txid, vout }, prev_output.clone(), local_owned)
 	}
 
 	fn generate_p2wsh_script_pubkey() -> ScriptBuf {