Merge pull request #3842 from optout21/shared-input

Add Shared Input support in interactive TX construction

Author: wpaulino

lightning/src/ln/channel.rs

@@ -58,7 +58,7 @@ use crate::ln::channelmanager::{
 use crate::ln::interactivetxs::{
 	calculate_change_output_value, get_output_weight, AbortReason, HandleTxCompleteResult,
 	InteractiveTxConstructor, InteractiveTxConstructorArgs, InteractiveTxMessageSend,
-	InteractiveTxMessageSendResult, InteractiveTxSigningSession, OutputOwned, SharedOwnedOutput,
+	InteractiveTxMessageSendResult, InteractiveTxSigningSession, SharedOwnedOutput,
 	TX_COMMON_FIELDS_WEIGHT,
 };
 use crate::ln::msgs;
@@ -2785,24 +2785,12 @@ where
 		// Note: For the error case when the inputs are insufficient, it will be handled after
 		// the `calculate_change_output_value` call below
 		let mut funding_outputs = Vec::new();
-		let mut expected_remote_shared_funding_output = None;
 
 		let shared_funding_output = TxOut {
 			value: Amount::from_sat(self.funding.get_value_satoshis()),
 			script_pubkey: self.funding.get_funding_redeemscript().to_p2wsh(),
 		};
 
-		if self.funding.is_outbound() {
-			funding_outputs.push(
-				OutputOwned::Shared(SharedOwnedOutput::new(
-					shared_funding_output, self.dual_funding_context.our_funding_satoshis,
-				))
-			);
-		} else {
-			let TxOut { value, script_pubkey } = shared_funding_output;
-			expected_remote_shared_funding_output = Some((script_pubkey, value.to_sat()));
-		}
-
 		// Optionally add change output
 		let change_script = if let Some(script) = change_destination_opt {
 			script
@@ -2812,7 +2800,8 @@ where
 		};
 		let change_value_opt = calculate_change_output_value(
 			self.funding.is_outbound(), self.dual_funding_context.our_funding_satoshis,
-			&funding_inputs, &funding_outputs,
+			&funding_inputs, None,
+			&shared_funding_output.script_pubkey, &funding_outputs,
 			self.dual_funding_context.funding_feerate_sat_per_1000_weight,
 			change_script.minimal_non_dust().to_sat(),
 		)?;
@@ -2827,7 +2816,7 @@ where
 			// Check dust limit again
 			if change_value_decreased_with_fee > self.context.holder_dust_limit_satoshis {
 				change_output.value = Amount::from_sat(change_value_decreased_with_fee);
-				funding_outputs.push(OutputOwned::Single(change_output));
+				funding_outputs.push(change_output);
 			}
 		}
 
@@ -2840,8 +2829,9 @@ where
 			is_initiator: self.funding.is_outbound(),
 			funding_tx_locktime: self.dual_funding_context.funding_tx_locktime,
 			inputs_to_contribute: funding_inputs,
+			shared_funding_input: None,
+			shared_funding_output: SharedOwnedOutput::new(shared_funding_output, self.dual_funding_context.our_funding_satoshis),
 			outputs_to_contribute: funding_outputs,
-			expected_remote_shared_funding_output,
 		};
 		let mut tx_constructor = InteractiveTxConstructor::new(constructor_args)?;
 		let msg = tx_constructor.take_initiator_first_message();
@@ -12036,6 +12026,10 @@ where
 			funding_feerate_sat_per_1000_weight: msg.funding_feerate_sat_per_1000_weight,
 			our_funding_inputs: our_funding_inputs.clone(),
 		};
+		let shared_funding_output = TxOut {
+			value: Amount::from_sat(funding.get_value_satoshis()),
+			script_pubkey: funding.get_funding_redeemscript().to_p2wsh(),
+		};
 
 		let interactive_tx_constructor = Some(InteractiveTxConstructor::new(
 			InteractiveTxConstructorArgs {
@@ -12047,8 +12041,9 @@ where
 				funding_tx_locktime: dual_funding_context.funding_tx_locktime,
 				is_initiator: false,
 				inputs_to_contribute: our_funding_inputs,
+				shared_funding_input: None,
+				shared_funding_output: SharedOwnedOutput::new(shared_funding_output, our_funding_satoshis),
 				outputs_to_contribute: Vec::new(),
-				expected_remote_shared_funding_output: Some((funding.get_funding_redeemscript().to_p2wsh(), funding.get_value_satoshis())),
 			}
 		).map_err(|err| {
 			let reason = ClosureReason::ProcessingError { err: err.to_string() };

lightning/src/ln/dual_funding_tests.rs

@@ -89,13 +89,14 @@ fn do_test_v2_channel_establishment(session: V2ChannelEstablishmentTestSession)
 	let tx_add_input_msg = TxAddInput {
 		channel_id,
 		serial_id: 2, // Even serial_id from initiator.
-		prevtx: initiator_funding_inputs[0].1.clone(),
+		prevtx: Some(initiator_funding_inputs[0].1.clone()),
 		prevtx_out: 0,
 		sequence: initiator_funding_inputs[0].0.sequence.0,
 		shared_input_txid: None,
 	};
-	let input_value =
-		tx_add_input_msg.prevtx.as_transaction().output[tx_add_input_msg.prevtx_out as usize].value;
+	let input_value = tx_add_input_msg.prevtx.as_ref().unwrap().as_transaction().output
+		[tx_add_input_msg.prevtx_out as usize]
+		.value;
 	assert_eq!(input_value.to_sat(), session.initiator_input_value_satoshis);
 
 	nodes[1].node.handle_tx_add_input(nodes[0].node.get_our_node_id(), &tx_add_input_msg);