From fb1956e23a39598c316c9bf584c492faea6019a2 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Viktor=20Tigerstr=C3=B6m?=
 <11711198+ViktorTigerstrom@users.noreply.github.com>
Date: Sat, 10 Dec 2022 23:02:00 +0100
Subject: [PATCH] Avoid unnecessary looping over all peers' channels

---
 lightning/src/ln/channelmanager.rs | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/lightning/src/ln/channelmanager.rs b/lightning/src/ln/channelmanager.rs
index 5ef0235eb..fefcefacc 100644
--- a/lightning/src/ln/channelmanager.rs
+++ b/lightning/src/ln/channelmanager.rs
@@ -6160,11 +6160,17 @@ where
 		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
 
 		if msg.channel_id == [0; 32] {
-			for chan in self.list_channels() {
-				if chan.counterparty.node_id == *counterparty_node_id {
-					// Untrusted messages from peer, we throw away the error if id points to a non-existent channel
-					let _ = self.force_close_channel_with_peer(&chan.channel_id, counterparty_node_id, Some(&msg.data), true);
-				}
+			let channel_ids: Vec<[u8; 32]> = {
+				let per_peer_state = self.per_peer_state.read().unwrap();
+				let peer_state_mutex_opt = per_peer_state.get(counterparty_node_id);
+				if let None = peer_state_mutex_opt { return; }
+				let mut peer_state_lock = peer_state_mutex_opt.unwrap().lock().unwrap();
+				let peer_state = &mut *peer_state_lock;
+				peer_state.channel_by_id.keys().cloned().collect()
+			};
+			for channel_id in channel_ids {
+				// Untrusted messages from peer, we throw away the error if id points to a non-existent channel
+				let _ = self.force_close_channel_with_peer(&channel_id, counterparty_node_id, Some(&msg.data), true);
 			}
 		} else {
 			{
-- 
2.39.5