Drop ChannelManager::block_disconnected() entirely

It is now entirely redundant with ChannelManager::update_best_block
and is still accessible via `Listen::block_disconnected`.

Author: TheBlueMatt

fuzz/src/full_stack.rs

@@ -27,6 +27,7 @@ use bitcoin::hashes::sha256::Hash as Sha256;
 use bitcoin::hash_types::{Txid, BlockHash, WPubkeyHash};
 
 use lightning::chain;
+use lightning::chain::Listen;
 use lightning::chain::chaininterface::{BroadcasterInterface, ConfirmationTarget, FeeEstimator};
 use lightning::chain::chainmonitor;
 use lightning::chain::transaction::OutPoint;
@@ -217,7 +218,7 @@ impl<'a> MoneyLossDetector<'a> {
 	fn disconnect_block(&mut self) {
 		if self.height > 0 && (self.max_height < 6 || self.height >= self.max_height - 6) {
 			let header = BlockHeader { version: 0x20000000, prev_blockhash: self.header_hashes[self.height - 1].0, merkle_root: Default::default(), time: self.header_hashes[self.height].1, bits: 42, nonce: 42 };
-			self.manager.block_disconnected(&header);
+			self.manager.block_disconnected(&header, self.height as u32);
 			self.monitor.block_disconnected(&header, self.height as u32);
 			self.height -= 1;
 			let removal_height = self.height;

lightning/src/ln/channelmanager.rs

@@ -3302,8 +3302,17 @@ where
 		self.update_best_block(&block.header, height);
 	}
 
-	fn block_disconnected(&self, header: &BlockHeader, _height: u32) {
-		ChannelManager::block_disconnected(self, header);
+	fn block_disconnected(&self, header: &BlockHeader, height: u32) {
+		assert_eq!(*self.last_block_hash.read().unwrap(), header.block_hash(),
+			"Blocks must be disconnected in chain-order - the disconnected header must be the last connected header");
+
+		let _persistence_guard = PersistenceNotifierGuard::new(&self.total_consistency_lock, &self.persistence_notifier);
+		let new_height = self.latest_block_height.fetch_sub(1, Ordering::AcqRel) as u32 - 1;
+		assert_eq!(new_height, height - 1,
+			"Blocks must be disconnected in chain-order - the disconnected block must have the correct height");
+		*self.last_block_hash.write().unwrap() = header.prev_blockhash;
+
+		self.do_chain_event(new_height, |channel| channel.update_best_block(new_height, header.time));
 	}
 }
 
@@ -3472,52 +3481,6 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
 		}
 	}
 
-	/// Updates channel state based on a disconnected block.
-	///
-	/// If necessary, the channel may be force-closed without letting the counterparty participate
-	/// in the shutdown.
-	pub fn block_disconnected(&self, header: &BlockHeader) {
-		// Note that we MUST NOT end up calling methods on self.chain_monitor here - we're called
-		// during initialization prior to the chain_monitor being fully configured in some cases.
-		// See the docs for `ChannelManagerReadArgs` for more.
-		let _persistence_guard = PersistenceNotifierGuard::new(&self.total_consistency_lock, &self.persistence_notifier);
-
-		assert_eq!(*self.last_block_hash.read().unwrap(), header.block_hash(),
-			"Blocks must be disconnected in chain-order - the disconnected header must be the last connected header");
-		let new_height = self.latest_block_height.fetch_sub(1, Ordering::AcqRel) as u32 - 1;
-		*self.last_block_hash.write().unwrap() = header.prev_blockhash;
-
-		let mut failed_channels = Vec::new();
-		{
-			let mut channel_lock = self.channel_state.lock().unwrap();
-			let channel_state = &mut *channel_lock;
-			let short_to_id = &mut channel_state.short_to_id;
-			let pending_msg_events = &mut channel_state.pending_msg_events;
-			channel_state.by_id.retain(|_,  v| {
-				if let Err(err_msg) = v.update_best_block(new_height, header.time) {
-					if let Some(short_id) = v.get_short_channel_id() {
-						short_to_id.remove(&short_id);
-					}
-					failed_channels.push(v.force_shutdown(true));
-					if let Ok(update) = self.get_channel_update(&v) {
-						pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate {
-							msg: update
-						});
-					}
-					pending_msg_events.push(events::MessageSendEvent::HandleError {
-						node_id: v.get_counterparty_node_id(),
-						action: msgs::ErrorAction::SendErrorMessage { msg: err_msg },
-					});
-					false
-				} else {
-					true
-				}
-			});
-		}
-
-		self.handle_init_event_channel_failures(failed_channels);
-	}
-
 	/// Blocks until ChannelManager needs to be persisted or a timeout is reached. It returns a bool
 	/// indicating whether persistence is necessary. Only one listener on
 	/// `await_persistable_update` or `await_persistable_update_timeout` is guaranteed to be woken

lightning/src/ln/functional_test_utils.rs

@@ -112,7 +112,7 @@ pub fn disconnect_blocks<'a, 'b, 'c, 'd>(node: &'a Node<'b, 'c, 'd>, count: u32)
 		let orig_header = node.blocks.borrow_mut().pop().unwrap();
 		assert!(orig_header.1 > 0); // Cannot disconnect genesis
 		node.chain_monitor.chain_monitor.block_disconnected(&orig_header.0, orig_header.1);
-		node.node.block_disconnected(&orig_header.0);
+		node.node.block_disconnected(&orig_header.0, orig_header.1);
 	}
 }