Merge pull request #27 from jbesraa/add-2760

2760

Author: dunxen

_posts/2023-12-06-#2760.md

@@ -0,0 +1,46 @@
+---
+layout: pr
+date: 2024-01-12
+title: "Fix infinite loop when closing a pre-funding channel"
+pr: 2760
+authors: [jbesraa]
+components: ["channel-establishment", "channel-funding"]
+host: jbesraa
+status: upcoming
+commit:
+---
+
+## Notes
+  Creating a channel involves exchanging multiple messages with a
+  connected peer, which does not always end up successfully.
+  Specifically, in the current implementation an infinite loop might occur 
+  in the funding step.
+  This bug was resulted from [ldk/2077].
+
+  [ldk/2760] Addresses this bug.
+
+        +-------+                         +-------+
+        |       |--(1)- open_channel ---->|       |
+        |       |<-(2)- accept_channel ----|       |
+        |       |--(3)- funding_created ->|       |
+        |       |<-(4)- funding_signed ---|       |
+        |       |--(5)- channel_ready --->|       |
+        |   A   |<-(6)- channel_ready  ---|   B   |
+        +-------+                         +-------+
+
+* Channel establishment(v1) is the process of creating a channel with a
+  connected peer, as detailed here [lightning/bolt02].
+
+## Questions
+1. Did you review the PR? [Concept ACK, approach ACK, tested ACK, or NACK](https://github.com/lightningdevkit/rust-lightning/blob/master/CONTRIBUTING.md#peer-review)?
+2. In the original code we have a loop inside `close_channel_internal`, 
+in which scenario it goes indefintly? 
+3. Why are we able to drop `force_close_channel_with_peer` from
+`close_channel_internal`, and `funding_created` msg from `SignerResumeUpdate`?
+4. What was the reasoning for promoting an `OutboundV1Channel` to a 
+`Channel` before receiving `funding_signed` prior to this PR? Why 
+do we no only do that promotion after receiving `funding_signed`?
+
+[lightning/bolt02]: https://github.com/lightning/bolts/blob/master/02-peer-protocol.md#channel-establishment.
+[ldk/2077]: https://github.com/lightningdevkit/rust-lightning/pull/2077
+[ldk/2760]: https://github.com/lightningdevkit/rust-lightning/pull/2760