Add basic async signer tests

This adds a new `async_signer_tests` module and populates it with some simple
checks for asynchronous handling of `funding_created` and `funding_signed`.

lightning/src/ln/async_signer_tests.rs

@@ -0,0 +1,132 @@
+// This file is Copyright its original authors, visible in version control
+// history.
+//
+// This file is licensed under the Apache License, Version 2.0 <LICENSE-APACHE
+// or http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your option.
+// You may not use this file except in accordance with one or both of these
+// licenses.
+
+//! Tests for asynchronous signing. These tests verify that the channel state machine behaves
+//! properly with a signer implementation that asynchronously derives signatures.
+
+use crate::events::{MessageSendEvent, MessageSendEventsProvider};
+use crate::ln::msgs::ChannelMessageHandler;
+
+use crate::ln::functional_test_utils::*;
+
+#[test]
+fn test_async_commitment_signature_for_funding_created() {
+	// Simulate acquiring the signature for `funding_created` asynchronously.
+	let chanmon_cfgs = create_chanmon_cfgs(2);
+	let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
+	let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
+	let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
+
+	nodes[0].node.create_channel(nodes[1].node.get_our_node_id(), 100000, 10001, 42, None).unwrap();
+
+	// nodes[0] --- open_channel --> nodes[1]
+	let mut open_chan_msg = get_event_msg!(nodes[0], MessageSendEvent::SendOpenChannel, nodes[1].node.get_our_node_id());
+	nodes[1].node.handle_open_channel(&nodes[0].node.get_our_node_id(), &open_chan_msg);
+
+	// nodes[0] <-- accept_channel --- nodes[1]
+	nodes[0].node.handle_accept_channel(&nodes[1].node.get_our_node_id(), &get_event_msg!(nodes[1], MessageSendEvent::SendAcceptChannel, nodes[0].node.get_our_node_id()));
+
+	// nodes[0] --- funding_created --> nodes[1]
+	//
+	// But! Let's make node[0]'s signer be unavailable: we should *not* broadcast a funding_created
+	// message...
+	let (temporary_channel_id, tx, _) = create_funding_transaction(&nodes[0], &nodes[1].node.get_our_node_id(), 100000, 42);
+	nodes[0].set_channel_signer_available(&nodes[1].node.get_our_node_id(), &temporary_channel_id, false);
+	nodes[0].node.funding_transaction_generated(&temporary_channel_id, &nodes[1].node.get_our_node_id(), tx.clone()).unwrap();
+	check_added_monitors(&nodes[0], 0);
+
+	{
+		let events = nodes[0].node.get_and_clear_pending_msg_events();
+		let n = events.len();
+		assert_eq!(n, 0, "expected no events generated from nodes[0], found {n}");
+	}
+
+	// Now re-enable the signer and simulate a retry. The temporary_channel_id won't work anymore so
+	// we have to dig out the real channel ID.
+	let chan_id = {
+		let per_peer_state = nodes[0].node.per_peer_state.read().unwrap();
+		let chan_lock = per_peer_state.get(&nodes[1].node.get_our_node_id()).unwrap().lock().unwrap();
+		let chan_ids = chan_lock.channel_by_id.keys().collect::<Vec<_>>();
+		let n = chan_ids.len();
+		assert_eq!(n, 1, "expected one channel, not {n}");
+		*chan_ids[0]
+	};
+
+	nodes[0].set_channel_signer_available(&nodes[1].node.get_our_node_id(), &chan_id, true);
+	nodes[0].node.signer_unblocked(Some((nodes[1].node.get_our_node_id(), chan_id)));
+
+	let mut funding_created_msg = get_event_msg!(nodes[0], MessageSendEvent::SendFundingCreated, nodes[1].node.get_our_node_id());
+	nodes[1].node.handle_funding_created(&nodes[0].node.get_our_node_id(), &funding_created_msg);
+	check_added_monitors(&nodes[1], 1);
+	expect_channel_pending_event(&nodes[1], &nodes[0].node.get_our_node_id());
+
+	// nodes[0] <-- funding_signed --- nodes[1]
+	let funding_signed_msg = get_event_msg!(nodes[1], MessageSendEvent::SendFundingSigned, nodes[0].node.get_our_node_id());
+	nodes[0].node.handle_funding_signed(&nodes[1].node.get_our_node_id(), &funding_signed_msg);
+	check_added_monitors(&nodes[0], 1);
+	expect_channel_pending_event(&nodes[0], &nodes[1].node.get_our_node_id());
+}
+
+#[test]
+fn test_async_commitment_signature_for_funding_signed() {
+	// Simulate acquiring the signature for `funding_signed` asynchronously.
+	let chanmon_cfgs = create_chanmon_cfgs(2);
+	let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
+	let node_chanmgrs = create_node_chanmgrs(2, &node_cfgs, &[None, None]);
+	let nodes = create_network(2, &node_cfgs, &node_chanmgrs);
+
+	nodes[0].node.create_channel(nodes[1].node.get_our_node_id(), 100000, 10001, 42, None).unwrap();
+
+	// nodes[0] --- open_channel --> nodes[1]
+	let mut open_chan_msg = get_event_msg!(nodes[0], MessageSendEvent::SendOpenChannel, nodes[1].node.get_our_node_id());
+	nodes[1].node.handle_open_channel(&nodes[0].node.get_our_node_id(), &open_chan_msg);
+
+	// nodes[0] <-- accept_channel --- nodes[1]
+	nodes[0].node.handle_accept_channel(&nodes[1].node.get_our_node_id(), &get_event_msg!(nodes[1], MessageSendEvent::SendAcceptChannel, nodes[0].node.get_our_node_id()));
+
+	// nodes[0] --- funding_created --> nodes[1]
+	let (temporary_channel_id, tx, _) = create_funding_transaction(&nodes[0], &nodes[1].node.get_our_node_id(), 100000, 42);
+	nodes[0].node.funding_transaction_generated(&temporary_channel_id, &nodes[1].node.get_our_node_id(), tx.clone()).unwrap();
+	check_added_monitors(&nodes[0], 0);
+
+	let mut funding_created_msg = get_event_msg!(nodes[0], MessageSendEvent::SendFundingCreated, nodes[1].node.get_our_node_id());
+
+	// Now let's make node[1]'s signer be unavailable while handling the `funding_created`. It should
+	// *not* broadcast a `funding_signed`...
+	nodes[1].set_channel_signer_available(&nodes[0].node.get_our_node_id(), &temporary_channel_id, false);
+	nodes[1].node.handle_funding_created(&nodes[0].node.get_our_node_id(), &funding_created_msg);
+	check_added_monitors(&nodes[1], 1);
+
+	{
+		let events = nodes[1].node.get_and_clear_pending_msg_events();
+		let n = events.len();
+		assert_eq!(n, 0, "expected no events generated from nodes[1], found {n}");
+	}
+
+	// Now re-enable the signer and simulate a retry. The temporary_channel_id won't work anymore so
+	// we have to dig out the real channel ID.
+	let chan_id = {
+		let per_peer_state = nodes[1].node.per_peer_state.read().unwrap();
+		let chan_lock = per_peer_state.get(&nodes[0].node.get_our_node_id()).unwrap().lock().unwrap();
+		let chan_ids = chan_lock.channel_by_id.keys().collect::<Vec<_>>();
+		let n = chan_ids.len();
+		assert_eq!(n, 1, "expected one channel, not {n}");
+		*chan_ids[0]
+	};
+	nodes[1].set_channel_signer_available(&nodes[0].node.get_our_node_id(), &chan_id, true);
+	nodes[1].node.signer_unblocked(Some((nodes[0].node.get_our_node_id(), chan_id)));
+
+	expect_channel_pending_event(&nodes[1], &nodes[0].node.get_our_node_id());
+
+	// nodes[0] <-- funding_signed --- nodes[1]
+	let funding_signed_msg = get_event_msg!(nodes[1], MessageSendEvent::SendFundingSigned, nodes[0].node.get_our_node_id());
+	nodes[0].node.handle_funding_signed(&nodes[1].node.get_our_node_id(), &funding_signed_msg);
+	check_added_monitors(&nodes[0], 1);
+	expect_channel_pending_event(&nodes[0], &nodes[1].node.get_our_node_id());
+}

lightning/src/ln/channel.rs

@@ -2056,7 +2056,6 @@ impl<SP: Deref> ChannelContext<SP> where SP::Target: SignerProvider  {
 			}
 		}
 	}
-
 }
 
 // Internal utility functions for channels

lightning/src/ln/functional_test_utils.rs

@@ -2084,12 +2084,13 @@ macro_rules! expect_channel_shutdown_state {
 }
 
 #[cfg(any(test, ldk_bench, feature = "_test_utils"))]
-pub fn expect_channel_pending_event<'a, 'b, 'c, 'd>(node: &'a Node<'b, 'c, 'd>, expected_counterparty_node_id: &PublicKey) {
+pub fn expect_channel_pending_event<'a, 'b, 'c, 'd>(node: &'a Node<'b, 'c, 'd>, expected_counterparty_node_id: &PublicKey) -> ChannelId {
 	let events = node.node.get_and_clear_pending_events();
 	assert_eq!(events.len(), 1);
-	match events[0] {
-		crate::events::Event::ChannelPending { ref counterparty_node_id, .. } => {
+	match &events[0] {
+		crate::events::Event::ChannelPending { channel_id, counterparty_node_id, .. } => {
 			assert_eq!(*expected_counterparty_node_id, *counterparty_node_id);
+			*channel_id
 		},
 		_ => panic!("Unexpected event"),
 	}

lightning/src/ln/mod.rs

@@ -70,6 +70,9 @@ mod monitor_tests;
 #[cfg(test)]
 #[allow(unused_mut)]
 mod shutdown_tests;
+#[cfg(test)]
+#[allow(unused_mut)]
+mod async_signer_tests;
 
 pub use self::peer_channel_encryptor::LN_MAX_MSG_LEN;