expose channel_reserve_satoshis

exposes channel_reserve_satoshis by adding it to CommonAcceptChannelFields for the user to ascertain the value set by the counterparty

Author: Prabhat1308

lightning/src/ln/channel.rs

@@ -11442,6 +11442,7 @@ where
 				commitment_feerate_sat_per_1000_weight: self.context.feerate_per_kw as u32,
 				to_self_delay: self.funding.get_holder_selected_contest_delay(),
 				max_accepted_htlcs: self.context.holder_max_accepted_htlcs,
+				channel_reserve_satoshis: self.funding.holder_selected_channel_reserve_satoshis,
 				funding_pubkey: keys.funding_pubkey,
 				revocation_basepoint: keys.revocation_basepoint.to_public_key(),
 				payment_basepoint: keys.payment_point,
@@ -11978,6 +11979,7 @@ where
 				commitment_feerate_sat_per_1000_weight: self.context.feerate_per_kw,
 				to_self_delay: self.funding.get_holder_selected_contest_delay(),
 				max_accepted_htlcs: self.context.holder_max_accepted_htlcs,
+				channel_reserve_satoshis: self.funding.holder_selected_channel_reserve_satoshis,
 				funding_pubkey: keys.funding_pubkey,
 				revocation_basepoint: keys.revocation_basepoint.to_public_key(),
 				payment_basepoint: keys.payment_point,

lightning/src/ln/channel_acceptance_tests.rs

@@ -225,11 +225,16 @@ fn do_test_manual_inbound_accept_with_override(
 
 	nodes[2].node.handle_open_channel(node_a, &open_channel_msg);
 	let events = nodes[2].node.get_and_clear_pending_events();
-	match events[0] {
-		Event::OpenChannelRequest { temporary_channel_id, .. } => nodes[2]
-			.node
-			.accept_inbound_channel(&temporary_channel_id, &node_a, 23, config_overrides)
-			.unwrap(),
+	match &events[0] {
+		Event::OpenChannelRequest { temporary_channel_id, params, .. } => {
+			// Test that channel_reserve_satoshis is properly exposed in Event::OpenChannelRequest
+			assert_eq!(params.channel_reserve_satoshis, open_channel_msg.channel_reserve_satoshis);
+
+			nodes[2]
+				.node
+				.accept_inbound_channel(temporary_channel_id, &node_a, 23, config_overrides)
+				.unwrap()
+		},
 		_ => panic!("Unexpected event"),
 	}
 	get_event_msg!(nodes[2], MessageSendEvent::SendAcceptChannel, node_a)

lightning/src/ln/msgs.rs

@@ -224,6 +224,8 @@ pub struct CommonOpenChannelFields {
 	pub to_self_delay: u16,
 	/// The maximum number of inbound HTLCs towards channel initiator
 	pub max_accepted_htlcs: u16,
+	/// The minimum value unencumbered by HTLCs for the counterparty to keep in the channel
+	pub channel_reserve_satoshis: u64,
 	/// The channel initiator's key controlling the funding transaction
 	pub funding_pubkey: PublicKey,
 	/// Used to derive a revocation key for transactions broadcast by counterparty
@@ -259,6 +261,7 @@ impl CommonOpenChannelFields {
 			commitment_feerate_sat_per_1000_weight: self.commitment_feerate_sat_per_1000_weight,
 			to_self_delay: self.to_self_delay,
 			max_accepted_htlcs: self.max_accepted_htlcs,
+			channel_reserve_satoshis: self.channel_reserve_satoshis,
 		}
 	}
 }
@@ -282,6 +285,8 @@ pub struct ChannelParameters {
 	pub to_self_delay: u16,
 	/// The maximum number of pending HTLCs towards the channel initiator.
 	pub max_accepted_htlcs: u16,
+	/// The minimum value unencumbered by HTLCs for the counterparty to keep in the channel
+	pub channel_reserve_satoshis: u64,
 }
 
 /// An [`open_channel`] message to be sent to or received from a peer.
@@ -3016,6 +3021,7 @@ impl LengthReadable for OpenChannel {
 				commitment_feerate_sat_per_1000_weight,
 				to_self_delay,
 				max_accepted_htlcs,
+				channel_reserve_satoshis,
 				funding_pubkey,
 				revocation_basepoint,
 				payment_basepoint,
@@ -3072,6 +3078,7 @@ impl LengthReadable for OpenChannelV2 {
 		let dust_limit_satoshis: u64 = Readable::read(r)?;
 		let max_htlc_value_in_flight_msat: u64 = Readable::read(r)?;
 		let htlc_minimum_msat: u64 = Readable::read(r)?;
+		let channel_reserve_satoshis: u64 = Readable::read(r)?;
 		let to_self_delay: u16 = Readable::read(r)?;
 		let max_accepted_htlcs: u16 = Readable::read(r)?;
 		let locktime: u32 = Readable::read(r)?;
@@ -3103,6 +3110,7 @@ impl LengthReadable for OpenChannelV2 {
 				commitment_feerate_sat_per_1000_weight,
 				to_self_delay,
 				max_accepted_htlcs,
+				channel_reserve_satoshis,
 				funding_pubkey,
 				revocation_basepoint,
 				payment_basepoint,
@@ -4708,6 +4716,7 @@ mod tests {
 				commitment_feerate_sat_per_1000_weight: 821716,
 				to_self_delay: 49340,
 				max_accepted_htlcs: 49340,
+				channel_reserve_satoshis: 8665828695742877976,
 				funding_pubkey: pubkey_1,
 				revocation_basepoint: pubkey_2,
 				payment_basepoint: pubkey_3,
@@ -4816,6 +4825,7 @@ mod tests {
 				htlc_minimum_msat: 2316138423780173,
 				to_self_delay: 49340,
 				max_accepted_htlcs: 49340,
+				channel_reserve_satoshis: 8665828695742877976,
 				funding_pubkey: pubkey_1,
 				revocation_basepoint: pubkey_2,
 				payment_basepoint: pubkey_3,