add manually_signal_channel_ready config option

Author: johncantrell97

lightning/src/ln/channel.rs

@@ -628,6 +628,14 @@ pub(super) struct Channel<Signer: ChannelSigner> {
 	/// `accept_inbound_channel`, and `funding_created` should therefore not execute successfully.
 	inbound_awaiting_accept: bool,
 
+	/// A flag that indicates whether the channel requires the user to signal readiness to send
+	/// the `msgs::ChannelReady` message.  This is only set to true if the channel was created with a
+	/// `ChannelHandshakeConfig::manually_signal_channel_ready` flag set to true.
+	/// 
+	/// When a user signals readiness via `ChannelManager::signal_channel_readiness` this flag is
+	/// flipped to false.
+	requires_manual_readiness_signal: bool,
+
 	/// The hash of the block in which the funding transaction was included.
 	funding_tx_confirmed_in: Option<BlockHash>,
 	funding_tx_confirmation_height: u32,
@@ -1065,6 +1073,7 @@ impl<Signer: WriteableEcdsaChannelSigner> Channel<Signer> {
 			target_closing_feerate_sats_per_kw: None,
 
 			inbound_awaiting_accept: false,
+			requires_manual_readiness_signal: config.channel_handshake_config.manually_signal_channel_ready,
 
 			funding_tx_confirmed_in: None,
 			funding_tx_confirmation_height: 0,
@@ -1409,6 +1418,7 @@ impl<Signer: WriteableEcdsaChannelSigner> Channel<Signer> {
 			target_closing_feerate_sats_per_kw: None,
 
 			inbound_awaiting_accept: true,
+			requires_manual_readiness_signal: config.channel_handshake_config.manually_signal_channel_ready,
 
 			funding_tx_confirmed_in: None,
 			funding_tx_confirmation_height: 0,
@@ -5305,6 +5315,10 @@ impl<Signer: WriteableEcdsaChannelSigner> Channel<Signer> {
 		self.inbound_awaiting_accept
 	}
 
+	pub fn requires_manual_readiness_signal(&self) -> bool {
+		self.requires_manual_readiness_signal
+	}
+
 	/// Sets this channel to accepting 0conf, must be done before `get_accept_channel`
 	pub fn set_0conf(&mut self) {
 		assert!(self.inbound_awaiting_accept);
@@ -6459,6 +6473,8 @@ impl<Signer: WriteableEcdsaChannelSigner> Writeable for Channel<Signer> {
 		// we write the high bytes as an option here.
 		let user_id_high_opt = Some((self.user_id >> 64) as u64);
 
+		let requires_manual_readiness_signal = Some(self.requires_manual_readiness_signal);
+		
 		write_tlv_fields!(writer, {
 			(0, self.announcement_sigs, option),
 			// minimum_depth and counterparty_selected_channel_reserve_satoshis used to have a
@@ -6484,6 +6500,7 @@ impl<Signer: WriteableEcdsaChannelSigner> Writeable for Channel<Signer> {
 			(23, channel_ready_event_emitted, option),
 			(25, user_id_high_opt, option),
 			(27, self.channel_keys_id, required),
+			(29, requires_manual_readiness_signal, option)
 		});
 
 		Ok(())
@@ -6755,6 +6772,7 @@ impl<'a, 'b, 'c, ES: Deref, SP: Deref> ReadableArgs<(&'a ES, &'b SP, u32, &'c Ch
 
 		let mut user_id_high_opt: Option<u64> = None;
 		let mut channel_keys_id: Option<[u8; 32]> = None;
+		let mut requires_manual_readiness_signal: Option<bool> = Some(false);
 
 		read_tlv_fields!(reader, {
 			(0, announcement_sigs, option),
@@ -6775,6 +6793,7 @@ impl<'a, 'b, 'c, ES: Deref, SP: Deref> ReadableArgs<(&'a ES, &'b SP, u32, &'c Ch
 			(23, channel_ready_event_emitted, option),
 			(25, user_id_high_opt, option),
 			(27, channel_keys_id, option),
+			(29, requires_manual_readiness_signal, option),
 		});
 
 		let (channel_keys_id, holder_signer) = if let Some(channel_keys_id) = channel_keys_id {
@@ -6885,6 +6904,7 @@ impl<'a, 'b, 'c, ES: Deref, SP: Deref> ReadableArgs<(&'a ES, &'b SP, u32, &'c Ch
 			target_closing_feerate_sats_per_kw,
 
 			inbound_awaiting_accept: false,
+			requires_manual_readiness_signal: requires_manual_readiness_signal.unwrap(),
 
 			funding_tx_confirmed_in,
 			funding_tx_confirmation_height,

lightning/src/util/config.rs

@@ -149,6 +149,17 @@ pub struct ChannelHandshakeConfig {
 	/// Maximum value: 1,000,000, any values larger than 1 Million will be treated as 1 Million (or 100%)
 	///                instead, although channel negotiations will fail in that case.
 	pub their_channel_reserve_proportional_millionths: u32,
+	/// If this is set to true, the user needs to manually signal readiness for an inbound channel.
+	///
+	/// When set to true, [`Event::PendingChannelReady`] will be triggered once LDK has seen sufficient
+	/// confirmations of the funding transaction. In that case, a [`msgs::ChannelReady`] message will not be 
+	/// sent to the counterparty node unless the user explicitly chooses to signal readiness.
+	///
+	/// Default value: false.
+	///
+	/// [`Event::PendingChannelReady`]: crate::util::events::Event::PendingChannelReady
+	/// [`msgs::ChannelReady`]: crate::ln::msgs::ChannelReady
+	pub manually_signal_channel_ready: bool,
 	#[cfg(anchors)]
 	/// If set, we attempt to negotiate the `anchors_zero_fee_htlc_tx`option for outbound channels.
 	///
@@ -183,6 +194,7 @@ impl Default for ChannelHandshakeConfig {
 			announced_channel: false,
 			commit_upfront_shutdown_pubkey: true,
 			their_channel_reserve_proportional_millionths: 10_000,
+			manually_signal_channel_ready: false,
 			#[cfg(anchors)]
 			negotiate_anchors_zero_fee_htlc_tx: false,
 		}