Send funding_locked immediately for inbound channels with 0conf

Author: TheBlueMatt

lightning/src/ln/channel.rs

@@ -2042,7 +2042,7 @@ impl<Signer: Sign> Channel<Signer> {
 		&self.get_counterparty_pubkeys().funding_pubkey
 	}
 
-	pub fn funding_created<L: Deref>(&mut self, msg: &msgs::FundingCreated, best_block: BestBlock, logger: &L) -> Result<(msgs::FundingSigned, ChannelMonitor<Signer>), ChannelError> where L::Target: Logger {
+	pub fn funding_created<L: Deref>(&mut self, msg: &msgs::FundingCreated, best_block: BestBlock, logger: &L) -> Result<(msgs::FundingSigned, ChannelMonitor<Signer>, Option<msgs::FundingLocked>), ChannelError> where L::Target: Logger {
 		if self.is_outbound() {
 			return Err(ChannelError::Close("Received funding_created for an outbound channel?".to_owned()));
 		}
@@ -2117,7 +2117,7 @@ impl<Signer: Sign> Channel<Signer> {
 		Ok((msgs::FundingSigned {
 			channel_id: self.channel_id,
 			signature
-		}, channel_monitor))
+		}, channel_monitor, self.check_get_funding_locked(0)))
 	}
 
 	/// Handles a funding_signed message from the remote end.
@@ -6605,7 +6605,7 @@ mod tests {
 		}]};
 		let funding_outpoint = OutPoint{ txid: tx.txid(), index: 0 };
 		let funding_created_msg = node_a_chan.get_outbound_funding_created(tx.clone(), funding_outpoint, &&logger).unwrap();
-		let (funding_signed_msg, _) = node_b_chan.funding_created(&funding_created_msg, best_block, &&logger).unwrap();
+		let (funding_signed_msg, _, _) = node_b_chan.funding_created(&funding_created_msg, best_block, &&logger).unwrap();
 
 		// Node B --> Node A: funding signed
 		let _ = node_a_chan.funding_signed(&funding_signed_msg, best_block, &&logger);

lightning/src/ln/channelmanager.rs

@@ -2529,6 +2529,9 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
 				action: msgs::ErrorAction::IgnoreError
 			});
 		}
+		if chan.get_short_channel_id().is_none() {
+			return Err(LightningError{err: "Channel not yet established".to_owned(), action: msgs::ErrorAction::IgnoreError});
+		}
 		log_trace!(self.logger, "Attempting to generate broadcast channel update for channel {}", log_bytes!(chan.channel_id()));
 		self.get_channel_update_for_unicast(chan)
 	}
@@ -2540,7 +2543,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
 	/// May be called with channel_state already locked!
 	fn get_channel_update_for_unicast(&self, chan: &Channel<Signer>) -> Result<msgs::ChannelUpdate, LightningError> {
 		log_trace!(self.logger, "Attempting to generate channel update for channel {}", log_bytes!(chan.channel_id()));
-		let short_channel_id = match chan.get_short_channel_id() {
+		let short_channel_id = match chan.get_short_channel_id().or(chan.latest_inbound_scid_alias()) {
 			None => return Err(LightningError{err: "Channel not yet established".to_owned(), action: msgs::ErrorAction::IgnoreError}),
 			Some(id) => id,
 		};
@@ -4489,7 +4492,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
 	}
 
 	fn internal_funding_created(&self, counterparty_node_id: &PublicKey, msg: &msgs::FundingCreated) -> Result<(), MsgHandleErrInternal> {
-		let ((funding_msg, monitor), mut chan) = {
+		let ((funding_msg, monitor, mut funding_locked), mut chan) = {
 			let best_block = *self.best_block.read().unwrap();
 			let mut channel_lock = self.channel_state.lock().unwrap();
 			let channel_state = &mut *channel_lock;
@@ -4524,7 +4527,8 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
 					// hasn't persisted to disk yet - we can't lose money on a transaction that we haven't
 					// accepted payment from yet. We do, however, need to wait to send our funding_locked
 					// until we have persisted our monitor.
-					chan.monitor_update_failed(false, false, false, Vec::new(), Vec::new(), Vec::new());
+					chan.monitor_update_failed(false, false, funding_locked.is_some(), Vec::new(), Vec::new(), Vec::new());
+					funding_locked = None; // Don't send the funding_locked now
 				},
 			}
 		}
@@ -4539,6 +4543,9 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
 					node_id: counterparty_node_id.clone(),
 					msg: funding_msg,
 				});
+				if let Some(msg) = funding_locked {
+					send_funding_locked!(channel_state.short_to_id, channel_state.pending_msg_events, chan, msg);
+				}
 				e.insert(chan);
 			}
 		}

lightning/src/ln/priv_short_conf_tests.rs

@@ -547,6 +547,9 @@ fn test_simple_0_conf_channel() {
 	// If our peer tells us they will accept our channel with 0 confs, and we funded the channel,
 	// we should trust the funding won't be double-spent (assuming `trust_own_funding_0conf` is
 	// set)!
+	// Further, if we `accept_inbound_channel_from_trusted_peer_0conf`, funding locked messages
+	// should fly immediately and the channel should be available for use as soon as they are
+	// received.
 
 	let chanmon_cfgs = create_chanmon_cfgs(2);
 	let node_cfgs = create_node_cfgs(2, &chanmon_cfgs);
@@ -579,11 +582,38 @@ fn test_simple_0_conf_channel() {
 
 	nodes[1].node.handle_funding_created(&nodes[0].node.get_our_node_id(), &funding_created);
 	check_added_monitors!(nodes[1], 1);
-	let funding_signed = 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);
-	check_added_monitors!(nodes[0], 1);
+	let bs_signed_locked = nodes[1].node.get_and_clear_pending_msg_events();
+	assert_eq!(bs_signed_locked.len(), 2);
+	let as_funding_locked;
+	match &bs_signed_locked[0] {
+		MessageSendEvent::SendFundingSigned { node_id, msg } => {
+			assert_eq!(*node_id, nodes[0].node.get_our_node_id());
+			nodes[0].node.handle_funding_signed(&nodes[1].node.get_our_node_id(), &msg);
+			check_added_monitors!(nodes[0], 1);
+
+			assert_eq!(nodes[0].tx_broadcaster.txn_broadcasted.lock().unwrap().len(), 1);
+			assert_eq!(nodes[0].tx_broadcaster.txn_broadcasted.lock().unwrap().split_off(0)[0], tx);
+
+			as_funding_locked = get_event_msg!(nodes[0], MessageSendEvent::SendFundingLocked, nodes[1].node.get_our_node_id());
+		}
+		_ => panic!("Unexpected event"),
+	}
+	match &bs_signed_locked[1] {
+		MessageSendEvent::SendFundingLocked { node_id, msg } => {
+			assert_eq!(*node_id, nodes[0].node.get_our_node_id());
+			nodes[0].node.handle_funding_locked(&nodes[1].node.get_our_node_id(), &msg);
+		}
+		_ => panic!("Unexpected event"),
+	}
 
-	let as_funding_locked = get_event_msg!(nodes[0], MessageSendEvent::SendFundingLocked, nodes[1].node.get_our_node_id());
 	nodes[1].node.handle_funding_locked(&nodes[0].node.get_our_node_id(), &as_funding_locked);
+
+	let as_channel_update = get_event_msg!(nodes[0], MessageSendEvent::SendChannelUpdate, nodes[1].node.get_our_node_id());
+	let bs_channel_update = get_event_msg!(nodes[1], MessageSendEvent::SendChannelUpdate, nodes[0].node.get_our_node_id());
+
+	nodes[0].node.handle_channel_update(&nodes[1].node.get_our_node_id(), &bs_channel_update);
+	nodes[1].node.handle_channel_update(&nodes[0].node.get_our_node_id(), &as_channel_update);
+
+	assert_eq!(nodes[0].node.list_usable_channels().len(), 1);
+	assert_eq!(nodes[1].node.list_usable_channels().len(), 1);
 }