f re-DRY force-shutdown logic

Author: TheBlueMatt

lightning/src/ln/channel.rs

@@ -5338,73 +5338,8 @@ where
 		self.unbroadcasted_funding_txid(funding).filter(|_| self.is_batch_funding())
 	}
 
-	/// Shuts down this channel (no more calls into this Channel may be made afterwards except
-	/// those explicitly stated to be allowed after shutdown, e.g. some simple getters).
-	///
-	/// Only allowed for channels which never been used (i.e. have never broadcasted their funding
-	/// transaction).
-	fn abandon_unfunded_chan(
-		&mut self, funding: &FundingScope, mut closure_reason: ClosureReason,
-	) -> ShutdownResult {
-		assert!(!matches!(self.channel_state, ChannelState::ShutdownComplete));
-		assert!(!self.is_funding_broadcast());
-
-		let unbroadcasted_batch_funding_txid = self.unbroadcasted_batch_funding_txid(funding);
-		let unbroadcasted_funding_tx = self.unbroadcasted_funding(funding);
-
-		let monitor_update = if let Some(funding_txo) = funding.get_funding_txo() {
-			// If we haven't yet exchanged funding signatures (ie channel_state < AwaitingChannelReady),
-			// returning a channel monitor update here would imply a channel monitor update before
-			// we even registered the channel monitor to begin with, which is invalid.
-			// Thus, if we aren't actually at a point where we could conceivably broadcast the
-			// funding transaction, don't return a funding txo (which prevents providing the
-			// monitor update to the user, even if we return one).
-			// See test_duplicate_chan_id and test_pre_lockin_no_chan_closed_update for more.
-			if !self.channel_state.is_pre_funded_state() {
-				self.latest_monitor_update_id += 1;
-				let update = ChannelMonitorUpdate {
-					update_id: self.latest_monitor_update_id,
-					updates: vec![ChannelMonitorUpdateStep::ChannelForceClosed {
-						should_broadcast: false,
-					}],
-					channel_id: Some(self.channel_id()),
-				};
-				Some((self.get_counterparty_node_id(), funding_txo, self.channel_id(), update))
-			} else {
-				None
-			}
-		} else {
-			None
-		};
-
-		if let ClosureReason::HolderForceClosed { ref mut broadcasted_latest_txn, .. } =
-			&mut closure_reason
-		{
-			*broadcasted_latest_txn = Some(false);
-		}
-
-		self.channel_state = ChannelState::ShutdownComplete;
-		self.update_time_counter += 1;
-		ShutdownResult {
-			closure_reason,
-			monitor_update,
-			dropped_outbound_htlcs: Vec::new(),
-			unbroadcasted_batch_funding_txid,
-			channel_id: self.channel_id,
-			user_channel_id: self.user_id,
-			channel_capacity_satoshis: funding.get_value_satoshis(),
-			counterparty_node_id: self.counterparty_node_id,
-			unbroadcasted_funding_tx,
-			is_manual_broadcast: self.is_manual_broadcast,
-			channel_funding_txo: funding.get_funding_txo(),
-			last_local_balance_msat: funding.value_to_self_msat,
-		}
-	}
-
-	/// Shuts down this Channel (no more calls into this Channel may be made afterwards except
-	/// those explicitly stated to be alowed after shutdown, e.g. some simple getters).
-	pub fn force_shutdown(
-		&mut self, funding: &FundingScope, mut closure_reason: ClosureReason,
+	pub fn do_force_shutdown(
+		&mut self, funding: &FundingScope, mut closure_reason: ClosureReason, broadcast: bool,
 	) -> ShutdownResult {
 		// Note that we MUST only generate a monitor update that indicates force-closure - we're
 		// called during initialization prior to the chain_monitor in the encompassing ChannelManager
@@ -5413,7 +5348,7 @@ where
 		assert!(!matches!(self.channel_state, ChannelState::ShutdownComplete));
 
 		if !self.is_funding_broadcast() {
-			return self.abandon_unfunded_chan(funding, closure_reason);
+			debug_assert!(!broadcast);
 		}
 
 		// We go ahead and "free" any holding cell HTLCs or HTLCs we haven't yet committed to and
@@ -5446,7 +5381,7 @@ where
 				let update = ChannelMonitorUpdate {
 					update_id: self.latest_monitor_update_id,
 					updates: vec![ChannelMonitorUpdateStep::ChannelForceClosed {
-						should_broadcast: true,
+						should_broadcast: broadcast,
 					}],
 					channel_id: Some(self.channel_id()),
 				};
@@ -5463,7 +5398,7 @@ where
 		if let ClosureReason::HolderForceClosed { ref mut broadcasted_latest_txn, .. } =
 			&mut closure_reason
 		{
-			*broadcasted_latest_txn = Some(true);
+			*broadcasted_latest_txn = Some(broadcast);
 		}
 
 		self.channel_state = ChannelState::ShutdownComplete;
@@ -5484,6 +5419,25 @@ where
 		}
 	}
 
+	/// Shuts down this channel (no more calls into this Channel may be made afterwards except
+	/// those explicitly stated to be allowed after shutdown, e.g. some simple getters).
+	///
+	/// Only allowed for channels which never been used (i.e. have never broadcasted their funding
+	/// transaction).
+	fn abandon_unfunded_chan(
+		&mut self, funding: &FundingScope, closure_reason: ClosureReason,
+	) -> ShutdownResult {
+		self.do_force_shutdown(funding, closure_reason, false)
+	}
+
+	/// Shuts down this Channel (no more calls into this Channel may be made afterwards except
+	/// those explicitly stated to be alowed after shutdown, e.g. some simple getters).
+	pub fn force_shutdown(
+		&mut self, funding: &FundingScope, closure_reason: ClosureReason,
+	) -> ShutdownResult {
+		self.do_force_shutdown(funding, closure_reason, self.is_funding_broadcast())
+	}
+
 	/// Only allowed after [`FundingScope::channel_transaction_parameters`] is set.
 	#[rustfmt::skip]
 	fn get_funding_signed_msg<L: Deref>(