Add API and signaling to accept incoming channels at 0conf

[rust-lightning] / lightning / src / ln / channelmanager.rs

diff --git a/lightning/src/ln/channelmanager.rs b/lightning/src/ln/channelmanager.rs
index 5f65a66ce914caa8cb454a9d56663c251bbff073..acc1310fa7117806f2e40878c9cd76e6d4b373c5 100644 (file)
--- a/lightning/src/ln/channelmanager.rs
+++ b/lightning/src/ln/channelmanager.rs
@@ -4119,20 +4119,45 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                }
        }
 
-       /// Called to accept a request to open a channel after [`Event::OpenChannelRequest`] has been
-       /// triggered.
+       /// Accepts a request to open a channel after a [`Event::OpenChannelRequest`].
        ///
        /// The `temporary_channel_id` parameter indicates which inbound channel should be accepted,
        /// and the `counterparty_node_id` parameter is the id of the peer which has requested to open
        /// the channel.
        ///
-       /// For inbound channels, the `user_channel_id` parameter will be provided back in
+       /// The `user_channel_id` parameter will be provided back in
        /// [`Event::ChannelClosed::user_channel_id`] to allow tracking of which events correspond
-       /// with which `accept_inbound_channel` call.
+       /// with which `accept_inbound_channel`/`accept_inbound_channel_from_trusted_peer_0conf` call.
        ///
        /// [`Event::OpenChannelRequest`]: events::Event::OpenChannelRequest
        /// [`Event::ChannelClosed::user_channel_id`]: events::Event::ChannelClosed::user_channel_id
        pub fn accept_inbound_channel(&self, temporary_channel_id: &[u8; 32], counterparty_node_id: &PublicKey, user_channel_id: u64) -> Result<(), APIError> {
+               self.do_accept_inbound_channel(temporary_channel_id, counterparty_node_id, false, user_channel_id)
+       }
+
+       /// Accepts a request to open a channel after a [`events::Event::OpenChannelRequest`], treating
+       /// it as confirmed immediately.
+       ///
+       /// The `user_channel_id` parameter will be provided back in
+       /// [`Event::ChannelClosed::user_channel_id`] to allow tracking of which events correspond
+       /// with which `accept_inbound_channel`/`accept_inbound_channel_from_trusted_peer_0conf` call.
+       ///
+       /// Unlike [`ChannelManager::accept_inbound_channel`], this method accepts the incoming channel
+       /// and (if the counterparty agrees), enables forwarding of payments immediately.
+       ///
+       /// This fully trusts that the counterparty has honestly and correctly constructed the funding
+       /// transaction and blindly assumes that it will eventually confirm.
+       ///
+       /// If it does not confirm before we decide to close the channel, or if the funding transaction
+       /// does not pay to the correct script the correct amount, *you will lose funds*.
+       ///
+       /// [`Event::OpenChannelRequest`]: events::Event::OpenChannelRequest
+       /// [`Event::ChannelClosed::user_channel_id`]: events::Event::ChannelClosed::user_channel_id
+       pub fn accept_inbound_channel_from_trusted_peer_0conf(&self, temporary_channel_id: &[u8; 32], counterparty_node_id: &PublicKey, user_channel_id: u64) -> Result<(), APIError> {
+               self.do_accept_inbound_channel(temporary_channel_id, counterparty_node_id, true, user_channel_id)
+       }
+
+       fn do_accept_inbound_channel(&self, temporary_channel_id: &[u8; 32], counterparty_node_id: &PublicKey, accept_0conf: bool, user_channel_id: u64) -> Result<(), APIError> {
                let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
 
                let mut channel_state_lock = self.channel_state.lock().unwrap();
@@ -4145,6 +4170,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                if *counterparty_node_id != channel.get().get_counterparty_node_id() {
                                        return Err(APIError::APIMisuseError { err: "The passed counterparty_node_id doesn't match the channel's counterparty node_id".to_owned() });
                                }
+                               if accept_0conf { channel.get_mut().set_0conf(); }
                                channel_state.pending_msg_events.push(events::MessageSendEvent::SendAcceptChannel {
                                        node_id: channel.get().get_counterparty_node_id(),
                                        msg: channel.get_mut().accept_inbound_channel(user_channel_id),