Pass FundingTxContributions to ChannelManager::splice_channel

Using FundingTxContributions for ChannelManager::splice_channel allows
supporting both splice-in and splice-out using the same method, with a
descriptive enum for the contributions.

Author: jkczyz

lightning/src/ln/channel.rs

@@ -10637,8 +10637,8 @@ where
 	#[cfg(splicing)]
 	pub fn splice_channel(
 		&mut self, our_funding_contribution_satoshis: i64,
-		our_funding_inputs: Vec<(TxIn, Transaction, Weight)>, change_script: Option<ScriptBuf>,
-		funding_feerate_per_kw: u32, locktime: u32,
+		funding_tx_contributions: FundingTxContributions, funding_feerate_per_kw: u32,
+		locktime: u32,
 	) -> Result<msgs::SpliceInit, APIError> {
 		// Check if a splice has been initiated already.
 		// Note: only a single outstanding splice is supported (per spec)
@@ -10691,7 +10691,7 @@ where
 		// Check that inputs are sufficient to cover our contribution.
 		let _fee = check_v2_funding_inputs_sufficient(
 			our_funding_contribution.to_sat(),
-			&our_funding_inputs,
+			funding_tx_contributions.inputs(),
 			true,
 			true,
 			funding_feerate_per_kw,
@@ -10704,7 +10704,7 @@ where
 			),
 		})?;
 
-		for (_, tx, _) in our_funding_inputs.iter() {
+		for (_, tx, _) in funding_tx_contributions.inputs().iter() {
 			const MESSAGE_TEMPLATE: msgs::TxAddInput = msgs::TxAddInput {
 				channel_id: ChannelId([0; 32]),
 				serial_id: 0,
@@ -10721,9 +10721,6 @@ where
 			}
 		}
 
-		let funding_tx_contributions =
-			FundingTxContributions::InputsOnly { inputs: our_funding_inputs, change_script };
-
 		let prev_funding_input = self.funding.to_splice_funding_input();
 		let funding_negotiation_context = FundingNegotiationContext {
 			is_initiator: true,

lightning/src/ln/channelmanager.rs

@@ -31,8 +31,6 @@ use bitcoin::hashes::{Hash, HashEngine, HmacEngine};
 use bitcoin::secp256k1::Secp256k1;
 use bitcoin::secp256k1::{PublicKey, SecretKey};
 use bitcoin::{secp256k1, Sequence, SignedAmount};
-#[cfg(splicing)]
-use bitcoin::{ScriptBuf, TxIn, Weight};
 
 use crate::blinded_path::message::MessageForwardNode;
 use crate::blinded_path::message::{AsyncPaymentsContext, OffersContext};
@@ -57,6 +55,8 @@ use crate::events::{
 };
 use crate::events::{FundingInfo, PaidBolt12Invoice};
 use crate::ln::chan_utils::selected_commitment_sat_per_1000_weight;
+#[cfg(splicing)]
+use crate::ln::channel::FundingTxContributions;
 // Since this struct is returned in `list_channels` methods, expose it here in case users want to
 // construct one themselves.
 use crate::ln::channel::{
@@ -4437,13 +4437,12 @@ where
 	#[rustfmt::skip]
 	pub fn splice_channel(
 		&self, channel_id: &ChannelId, counterparty_node_id: &PublicKey, our_funding_contribution_satoshis: i64,
-		our_funding_inputs: Vec<(TxIn, Transaction, Weight)>, change_script: Option<ScriptBuf>,
-		funding_feerate_per_kw: u32, locktime: Option<u32>,
+		funding_tx_contributions: FundingTxContributions, funding_feerate_per_kw: u32, locktime: Option<u32>,
 	) -> Result<(), APIError> {
 		let mut res = Ok(());
 		PersistenceNotifierGuard::optionally_notify(self, || {
 			let result = self.internal_splice_channel(
-				channel_id, counterparty_node_id, our_funding_contribution_satoshis, our_funding_inputs, change_script, funding_feerate_per_kw, locktime
+				channel_id, counterparty_node_id, our_funding_contribution_satoshis, funding_tx_contributions, funding_feerate_per_kw, locktime
 			);
 			res = result;
 			match res {
@@ -4458,8 +4457,7 @@ where
 	#[cfg(splicing)]
 	fn internal_splice_channel(
 		&self, channel_id: &ChannelId, counterparty_node_id: &PublicKey,
-		our_funding_contribution_satoshis: i64,
-		our_funding_inputs: Vec<(TxIn, Transaction, Weight)>, change_script: Option<ScriptBuf>,
+		our_funding_contribution_satoshis: i64, funding_tx_contributions: FundingTxContributions,
 		funding_feerate_per_kw: u32, locktime: Option<u32>,
 	) -> Result<(), APIError> {
 		let per_peer_state = self.per_peer_state.read().unwrap();
@@ -4483,8 +4481,7 @@ where
 				if let Some(chan) = chan_phase_entry.get_mut().as_funded_mut() {
 					let msg = chan.splice_channel(
 						our_funding_contribution_satoshis,
-						our_funding_inputs,
-						change_script,
+						funding_tx_contributions,
 						funding_feerate_per_kw,
 						locktime,
 					)?;

lightning/src/ln/splicing_tests.rs

@@ -7,6 +7,7 @@
 // You may not use this file except in accordance with one or both of these
 // licenses.
 
+use crate::ln::channel::FundingTxContributions;
 use crate::ln::functional_test_utils::*;
 use crate::ln::msgs::{BaseMessageHandler, ChannelMessageHandler, MessageSendEvent};
 use crate::util::errors::APIError;
@@ -66,15 +67,16 @@ fn test_v1_splice_in() {
 		&initiator_node,
 		&[extra_splice_funding_input_sats],
 	);
+	let funding_tx_contributions =
+		FundingTxContributions::InputsOnly { inputs: funding_inputs, change_script: None };
 	// Initiate splice-in
 	let _res = initiator_node
 		.node
 		.splice_channel(
 			&channel_id,
 			&acceptor_node.node.get_our_node_id(),
 			splice_in_sats as i64,
-			funding_inputs,
-			None, // change_script
+			funding_tx_contributions,
 			funding_feerate_per_kw,
 			None, // locktime
 		)
@@ -316,14 +318,15 @@ fn test_v1_splice_in_negative_insufficient_inputs() {
 	let extra_splice_funding_input_sats = splice_in_sats - 1;
 	let funding_inputs =
 		create_dual_funding_utxos_with_prev_txs(&nodes[0], &[extra_splice_funding_input_sats]);
+	let funding_tx_contributions =
+		FundingTxContributions::InputsOnly { inputs: funding_inputs, change_script: None };
 
 	// Initiate splice-in, with insufficient input contribution
 	let res = nodes[0].node.splice_channel(
 		&channel_id,
 		&nodes[1].node.get_our_node_id(),
 		splice_in_sats as i64,
-		funding_inputs,
-		None, // change_script
+		funding_tx_contributions,
 		1024, // funding_feerate_per_kw,
 		None, // locktime
 	);