From 950ccc434046adb8527c9d3c066da482219b924a Mon Sep 17 00:00:00 2001
From: Matt Corallo <git@bluematt.me>
Date: Wed, 7 Sep 2022 17:51:16 +0000
Subject: [PATCH] Fetch our `InitFeatures` from `ChannelMessageHandler`

Like we now do for `NodeFeatures`, this converts to asking our
registered `ChannelMessageHandler` for our `InitFeatures` instead
of hard-coding them to the global LDK known set.

This allows handlers to set different feature bits based on what
our configuration actually supports rather than what LDK supports
in aggregate.
---
 lightning-net-tokio/src/lib.rs     | 1 +
 lightning/src/ln/channelmanager.rs | 4 ++++
 lightning/src/ln/msgs.rs           | 7 +++++++
 lightning/src/ln/peer_handler.rs   | 5 +++--
 lightning/src/util/test_utils.rs   | 3 +++
 5 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/lightning-net-tokio/src/lib.rs b/lightning-net-tokio/src/lib.rs
index 022b67fca..fafa9ef8a 100644
--- a/lightning-net-tokio/src/lib.rs
+++ b/lightning-net-tokio/src/lib.rs
@@ -614,6 +614,7 @@ mod tests {
 		fn handle_channel_reestablish(&self, _their_node_id: &PublicKey, _msg: &ChannelReestablish) {}
 		fn handle_error(&self, _their_node_id: &PublicKey, _msg: &ErrorMessage) {}
 		fn provided_node_features(&self) -> NodeFeatures { NodeFeatures::known() }
+		fn provided_init_features(&self, _their_node_id: &PublicKey) -> InitFeatures { InitFeatures::known() }
 	}
 	impl MessageSendEventsProvider for MsgHandler {
 		fn get_and_clear_pending_msg_events(&self) -> Vec<MessageSendEvent> {
diff --git a/lightning/src/ln/channelmanager.rs b/lightning/src/ln/channelmanager.rs
index afbd040b6..20fd5a38b 100644
--- a/lightning/src/ln/channelmanager.rs
+++ b/lightning/src/ln/channelmanager.rs
@@ -6124,6 +6124,10 @@ impl<Signer: Sign, M: Deref , T: Deref , K: Deref , F: Deref , L: Deref >
 	fn provided_node_features(&self) -> NodeFeatures {
 		NodeFeatures::known()
 	}
+
+	fn provided_init_features(&self, _their_init_features: &PublicKey) -> InitFeatures {
+		InitFeatures::known()
+	}
 }
 
 const SERIALIZATION_VERSION: u8 = 1;
diff --git a/lightning/src/ln/msgs.rs b/lightning/src/ln/msgs.rs
index a810731c6..fdcf5b05f 100644
--- a/lightning/src/ln/msgs.rs
+++ b/lightning/src/ln/msgs.rs
@@ -902,6 +902,13 @@ pub trait ChannelMessageHandler : MessageSendEventsProvider {
 	/// queried similarly and their feature flags are OR'd together to form the [`NodeFeatures`]
 	/// which are broadcasted in our node_announcement message.
 	fn provided_node_features(&self) -> NodeFeatures;
+
+	/// Gets the init feature flags which should be sent to the given peer. All available handlers
+	/// are queried similarly and their feature flags are OR'd together to form the [`InitFeatures`]
+	/// which are sent in our [`Init`] message.
+	///
+	/// Note that this method is called before [`Self::peer_connected`].
+	fn provided_init_features(&self, their_node_id: &PublicKey) -> InitFeatures;
 }
 
 /// A trait to describe an object which can receive routing messages.
diff --git a/lightning/src/ln/peer_handler.rs b/lightning/src/ln/peer_handler.rs
index 9d3b7aca8..02c9749d1 100644
--- a/lightning/src/ln/peer_handler.rs
+++ b/lightning/src/ln/peer_handler.rs
@@ -203,6 +203,7 @@ impl ChannelMessageHandler for ErroringMessageHandler {
 	fn peer_connected(&self, _their_node_id: &PublicKey, _msg: &msgs::Init) {}
 	fn handle_error(&self, _their_node_id: &PublicKey, _msg: &msgs::ErrorMessage) {}
 	fn provided_node_features(&self) -> NodeFeatures { NodeFeatures::empty() }
+	fn provided_init_features(&self, _their_node_id: &PublicKey) -> InitFeatures { InitFeatures::known() }
 }
 impl Deref for ErroringMessageHandler {
 	type Target = ErroringMessageHandler;
@@ -1052,7 +1053,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, OM: Deref, L: Deref, CM
 
 								peer.their_node_id = Some(their_node_id);
 								insert_node_id!();
-								let features = InitFeatures::known();
+								let features = self.message_handler.chan_handler.provided_init_features(&their_node_id);
 								let resp = msgs::Init { features, remote_network_address: filter_addresses(peer.their_net_address.clone()) };
 								self.enqueue_message(peer, &resp);
 								peer.awaiting_pong_timer_tick_intervals = 0;
@@ -1064,7 +1065,7 @@ impl<Descriptor: SocketDescriptor, CM: Deref, RM: Deref, OM: Deref, L: Deref, CM
 								peer.pending_read_is_header = true;
 								peer.their_node_id = Some(their_node_id);
 								insert_node_id!();
-								let features = InitFeatures::known();
+								let features = self.message_handler.chan_handler.provided_init_features(&their_node_id);
 								let resp = msgs::Init { features, remote_network_address: filter_addresses(peer.their_net_address.clone()) };
 								self.enqueue_message(peer, &resp);
 								peer.awaiting_pong_timer_tick_intervals = 0;
diff --git a/lightning/src/util/test_utils.rs b/lightning/src/util/test_utils.rs
index 42ac228c1..0ef05b7d1 100644
--- a/lightning/src/util/test_utils.rs
+++ b/lightning/src/util/test_utils.rs
@@ -360,6 +360,9 @@ impl msgs::ChannelMessageHandler for TestChannelMessageHandler {
 	fn provided_node_features(&self) -> NodeFeatures {
 		NodeFeatures::empty()
 	}
+	fn provided_init_features(&self, _their_init_features: &PublicKey) -> InitFeatures {
+		InitFeatures::known()
+	}
 }
 
 impl events::MessageSendEventsProvider for TestChannelMessageHandler {
-- 
2.39.5