staging

lightning/src/ln/channel.rs

@@ -54,6 +54,7 @@ use crate::chain::BestBlock;
 use crate::chain::chaininterface::{FeeEstimator, ConfirmationTarget, LowerBoundedFeeEstimator, fee_for_weight};
 use crate::chain::channelmonitor::{ChannelMonitor, ChannelMonitorUpdate, ChannelMonitorUpdateStep, LATENCY_GRACE_PERIOD_BLOCKS};
 use crate::chain::transaction::{OutPoint, TransactionData};
+use crate::sign::tx_builder::ChannelParameters;
 use crate::sign::ecdsa::EcdsaChannelSigner;
 use crate::sign::{EntropySource, ChannelSigner, SignerProvider, NodeSigner, Recipient};
 use crate::events::{ClosureReason, Event};
@@ -2237,6 +2238,15 @@ impl<SP: Deref> ChannelContext<SP> where SP::Target: SignerProvider {
 
 		let channel_keys_id = signer_provider.generate_channel_keys_id(true, channel_value_satoshis, user_id);
 		let holder_signer = signer_provider.derive_channel_signer(channel_value_satoshis, channel_keys_id);
+		let mut tx_builder = holder_signer.derive_tx_builder();
+		tx_builder.provide_holder_parameters(&ChannelTransactionParameters {
+			holder_pubkeys: holder_signer.pubkeys().clone(),
+			holder_selected_contest_delay: config.channel_handshake_config.our_to_self_delay,
+			is_outbound_from_holder: false,
+			counterparty_parameters: None,
+			funding_outpoint: None,
+			channel_type_features: channel_type.clone(),
+		});
 		let pubkeys = holder_signer.pubkeys().clone();
 
 		if config.channel_handshake_config.our_to_self_delay < BREAKDOWN_TIMEOUT {
@@ -8568,6 +8578,16 @@ impl<SP: Deref> OutboundV1Channel<SP> where SP::Target: SignerProvider {
 		let channel_keys_id = signer_provider.generate_channel_keys_id(false, channel_value_satoshis, user_id);
 		let holder_signer = signer_provider.derive_channel_signer(channel_value_satoshis, channel_keys_id);
 		let pubkeys = holder_signer.pubkeys().clone();
+		let mut tx_builder = holder_signer.derive_tx_builder();
+		let channel_type = get_initial_channel_type(&config, their_features);
+		tx_builder.provide_holder_parameters(&ChannelTransactionParameters {
+			holder_pubkeys: holder_signer.pubkeys().clone(),
+			holder_selected_contest_delay: config.channel_handshake_config.our_to_self_delay,
+			is_outbound_from_holder: true,
+			counterparty_parameters: None,
+			funding_outpoint: None,
+			channel_type_features: channel_type.clone(),
+		});
 
 		let context = ChannelContext::new_for_outbound_channel(
 			fee_estimator,

lightning/src/sign/mod.rs

@@ -84,6 +84,8 @@ pub mod taproot;
 #[cfg(custom_tx)]
 pub mod tx_builder;
 
+use tx_builder::SpecTxBuilder;
+
 /// Information about a spendable output to a P2WSH script.
 ///
 /// See [`SpendableOutputDescriptor::DelayedPaymentOutput`] for more details on how to spend this.
@@ -818,6 +820,9 @@ pub trait ChannelSigner {
 	///
 	/// channel_parameters.is_populated() MUST be true.
 	fn provide_channel_parameters(&mut self, channel_parameters: &ChannelTransactionParameters);
+
+	///Derive a txbuilder
+	fn derive_tx_builder(&self) -> SpecTxBuilder;
 }
 
 /// Specifies the recipient of an invoice.
@@ -1402,6 +1407,10 @@ impl ChannelSigner for InMemorySigner {
 		assert!(channel_parameters.is_populated(), "Channel parameters must be fully populated");
 		self.channel_parameters = Some(channel_parameters.clone());
 	}
+
+	fn derive_tx_builder(&self) -> SpecTxBuilder {
+		SpecTxBuilder::default()
+	}
 }
 
 const MISSING_PARAMS_ERR: &'static str =

lightning/src/sign/tx_builder.rs

@@ -14,14 +14,18 @@ use crate::prelude::*;
 
 /// Defines a trait for types that hold the static channel parameters.
 pub trait ChannelParameters {
+	/// Provides the parameters of the channel holder.
+	fn provide_holder_parameters(
+		&mut self, channel_parameters: &ChannelTransactionParameters,
+	);
 	/// Provides the parameters of the channel counterparty.
 	fn provide_counterparty_parameters(
 		&mut self, channel_parameters: &CounterpartyChannelTransactionParameters,
 	);
 	/// Provides the outpoint of the channel's funding output.
 	fn provide_funding_outpoint(&mut self, funding_outpoint: OutPoint);
 
-	/// This may be called at any point.
+	/// This will be called only after the holder parameters have been provided.
 	fn get_holder_parameters(&self) -> &ChannelTransactionParameters;
 	/// `channel_parameters.counterparty_parameters.is_some()` MUST be true.
 	/// This will be called only after the counterparty parameters have been provided.
@@ -61,36 +65,58 @@ pub trait TxBuilder: ChannelParameters {
 }
 
 /// A type that builds commitment transactions according to the Lightning Specification.
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, Default)]
 pub struct SpecTxBuilder {
-	channel_parameters: ChannelTransactionParameters,
-}
-
-impl From<ChannelTransactionParameters> for SpecTxBuilder {
-	/// May be called when only the holder channel parameters are known; the counterparty parameters and the funding
-	/// outpoint will be provided later.
-	fn from(channel_parameters: ChannelTransactionParameters) -> Self {
-		SpecTxBuilder { channel_parameters }
-	}
+	channel_parameters: Option<ChannelTransactionParameters>,
 }
 
 impl ChannelParameters for SpecTxBuilder {
+	fn provide_holder_parameters(&mut self, channel_parameters: &ChannelTransactionParameters) {
+		assert!(
+			self.channel_parameters.is_none()
+				|| self.channel_parameters.as_ref().unwrap() == channel_parameters
+		);
+		if self.channel_parameters.is_some() {
+			// The channel parameters were already set and they match, return early.
+			return;
+		}
+		self.channel_parameters = Some(channel_parameters.clone());
+	}
 	fn provide_counterparty_parameters(
 		&mut self, channel_parameters: &CounterpartyChannelTransactionParameters,
 	) {
-		todo!();
+		let params = self.channel_parameters.as_mut().unwrap();
+		assert!(
+			params.counterparty_parameters.is_none()
+				|| params.counterparty_parameters.as_ref().unwrap() == channel_parameters
+		);
+		if params.counterparty_parameters.is_some() {
+			// The channel parameters were already set and they match, return early.
+			return;
+		}
+		params.counterparty_parameters = Some(channel_parameters.clone());
 	}
 	fn provide_funding_outpoint(&mut self, funding_outpoint: OutPoint) {
-		todo!();
+		let params = self.channel_parameters.as_mut().unwrap();
+		assert!(params.counterparty_parameters.is_some());
+		assert!(
+			params.funding_outpoint.is_none()
+				|| params.funding_outpoint.unwrap() == funding_outpoint
+		);
+		if params.funding_outpoint.is_some() {
+			// The channel parameters were already set and they match, return early.
+			return;
+		}
+		params.funding_outpoint = Some(funding_outpoint);
 	}
 	fn get_holder_parameters(&self) -> &ChannelTransactionParameters {
-		todo!();
+		self.channel_parameters.as_ref().unwrap()
 	}
 	fn get_holder_and_counterparty_parameters(&self) -> &ChannelTransactionParameters {
-		todo!();
+		self.channel_parameters.as_ref().unwrap()
 	}
 	fn get_populated_parameters(&self) -> &ChannelTransactionParameters {
-		todo!();
+		self.channel_parameters.as_ref().unwrap()
 	}
 }