Add FundingSigned event

  If `manually_broadcast_outbound_channels` is set, LDK will emit this
  event after the counterparty node send the `FundingSigned` msg without
  broadcasting the funding transaction.

lightning/src/events/mod.rs

@@ -497,6 +497,29 @@ impl_writeable_tlv_based_enum!(PaymentFailureReason,
 /// written as it makes no sense to respond to it after reconnecting to peers).
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub enum Event {
+	/// Used to indicate that the counterparty node has sent `FundingSigned` msg but we are yet to
+	/// broadcast the funding transaction.
+	///
+	/// After you receive this event, you should broadcast the funding transaction and then call
+	//// [`ChannelManager::funding_transaction_broadcasted`]. <-- not implemtened yet
+	/// // should we have some timeout for this?
+	//// [`ChannelManager::funding_transaction_broadcasted`]: crate::ln::channelmanager::ChannelManager::funding_transaction_broadcasted
+	FundingSigned {
+		/// The `channel_id` indicating which channel has completed the `FundingSigned` stage.
+		channel_id: ChannelId,
+		/// The `user_channel_id` value passed in to [`ChannelManager::create_channel`] for outbound
+		/// channels, or to [`ChannelManager::accept_inbound_channel`] for inbound channels if
+		/// [`UserConfig::manually_accept_inbound_channels`] config flag is set to true. Otherwise
+		/// `user_channel_id` will be randomized for an inbound channel.  This may be zero for objects
+		/// serialized with LDK versions prior to 0.0.113.
+		///
+		/// [`ChannelManager::create_channel`]: crate::ln::channelmanager::ChannelManager::create_channel
+		/// [`ChannelManager::accept_inbound_channel`]: crate::ln::channelmanager::ChannelManager::accept_inbound_channel
+		/// [`UserConfig::manually_accept_inbound_channels`]: crate::util::config::UserConfig::manually_accept_inbound_channels
+		user_channel_id: u128,
+		/// The funding transaction which was signed by the counterparty.
+		funding_tx: Transaction,
+	},
 	/// Used to indicate that the client should generate a funding transaction with the given
 	/// parameters and then call [`ChannelManager::funding_transaction_generated`].
 	/// Generated in [`ChannelManager`] message handling.
@@ -1404,6 +1427,14 @@ impl Writeable for Event {
 				35u8.write(writer)?;
 				// Never write ConnectionNeeded events as buffered onion messages aren't serialized.
 			},
+			&Event::FundingSigned { ref channel_id, ref user_channel_id, ref funding_tx } => {
+				37u8.write(writer)?;
+				write_tlv_fields!(writer, {
+					(0, channel_id, required),
+					(2, user_channel_id, required),
+					(4, funding_tx, required),
+				});
+			},
 			// Note that, going forward, all new events must only write data inside of
 			// `write_tlv_fields`. Versions 0.0.101+ will ignore odd-numbered events that write
 			// data via `write_tlv_fields`.
@@ -1814,6 +1845,24 @@ impl MaybeReadable for Event {
 			},
 			// Note that we do not write a length-prefixed TLV for ConnectionNeeded events.
 			35u8 => Ok(None),
+			37u8 => {
+				let mut f = || {
+					let mut channel_id = ChannelId::new_zero();
+					let mut user_channel_id: u128 = 0;
+					let mut funding_tx = Transaction { version: 2, lock_time: LockTime::ZERO, input: Vec::new(), output: Vec::new() };
+					read_tlv_fields!(reader, {
+						(0, channel_id, required),
+						(2, user_channel_id, required),
+						(4, funding_tx, required),
+					});
+					Ok(Some(Event::FundingSigned {
+						channel_id,
+						user_channel_id,
+						funding_tx,
+					}))
+				};
+				f()
+			},
 			// Versions prior to 0.0.100 did not ignore odd types, instead returning InvalidValue.
 			// Version 0.0.100 failed to properly ignore odd types, possibly resulting in corrupt
 			// reads.