From: Matt Corallo <git@bluematt.me>
Date: Sat, 13 Nov 2021 21:28:49 +0000 (+0000)
Subject: XXX: BAD WIP
X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=commitdiff_plain;h=863f64bee9f19882178245500fea4abcaff62755;p=rust-lightning

XXX: BAD WIP
---

diff --git a/lightning/src/ln/channel.rs b/lightning/src/ln/channel.rs
index bda7d341..74622250 100644
--- a/lightning/src/ln/channel.rs
+++ b/lightning/src/ln/channel.rs
@@ -2430,7 +2430,10 @@ panic!();
 
 	fn check_state_for_htlc_msg(&self) -> Result<(), ChannelError> {
 		if (self.channel_state & (ChannelState::ChannelFunded as u32)) != (ChannelState::ChannelFunded as u32) {
-			return Err(ChannelError::Close("Got HTLC message when channel was not in an operational state".to_owned()));
+			let early_funding_locked_state = ChannelState::FundingSent as u32 | ChannelState::OurFundingLocked as u32;
+			if self.channel_state & early_funding_locked_state != early_funding_locked_state {
+				return Err(ChannelError::Close("Got HTLC message when channel was not in an operational state".to_owned()));
+			}
 		}
 		if self.channel_state & (ChannelState::PeerDisconnected as u32) == ChannelState::PeerDisconnected as u32 {
 			return Err(ChannelError::Close("Peer sent HTLC message when we needed a channel_reestablish".to_owned()));
@@ -4282,6 +4285,7 @@ panic!();
 
 	/// Returns true if this channel is fully established and not known to be closing.
 	/// Allowed in any state (including after shutdown)
+	#[inline]
 	pub fn is_usable(&self) -> bool {
 		let mask = ChannelState::ChannelFunded as u32 | BOTH_SIDES_SHUTDOWN_MASK;
 		(self.channel_state & mask) == (ChannelState::ChannelFunded as u32) && !self.monitor_pending_funding_locked
@@ -4290,10 +4294,26 @@ panic!();
 	/// Returns true if this channel is currently available for use. This is a superset of
 	/// is_usable() and considers things like the channel being temporarily disabled.
 	/// Allowed in any state (including after shutdown)
+	#[inline]
 	pub fn is_live(&self) -> bool {
 		self.is_usable() && (self.channel_state & (ChannelState::PeerDisconnected as u32) == 0)
 	}
 
+	/// Returns true if this channel is currently available for receiving inbound payments *to us*.
+	/// This may be true even if [`is_usable`] (or [`is_live`]) is *not* true, if our counterparty
+	/// is willing to forward payments to us with 0 confirmations on the funding transaction.
+	/// Note that payments received on this channel MUST NOT be forwarded unless we've marked the
+	/// channel trusted or [`is_usable`] is also true.
+	/// Allowed in any state (including after shutdown)
+	pub fn is_receivable(&self) -> bool {
+		let non_live_state_reqd = ChannelState::TheirFundingLocked as u32 | ChannelState::ChannelState::FundingSent as u32;
+		self.is_live() || (
+			(self.channel_state & BOTH_SIDES_SHUTDOWN_MASK) == 0 &&
+			(self.channel_state & ChannelState::PeerDisconnected as u32) == 0 &&
+			(self.channel_state & non_live_state_reqd) == non_live_state_reqd
+		)
+	}
+
 	/// Returns true if this channel has been marked as awaiting a monitor update to move forward.
 	/// Allowed in any state (including after shutdown)
 	pub fn is_awaiting_monitor_update(&self) -> bool {
diff --git a/lightning/src/ln/channelmanager.rs b/lightning/src/ln/channelmanager.rs
index b1ea5b2e..60eb5605 100644
--- a/lightning/src/ln/channelmanager.rs
+++ b/lightning/src/ln/channelmanager.rs
@@ -1274,6 +1274,7 @@ pub struct ChannelDetails {
 	///
 	/// This is a strict superset of `is_funding_locked`.
 	pub is_usable: bool,
+	pub is_receivable: bool,
 	/// True if this channel is (or will be) publicly-announced.
 	pub is_public: bool,
 }
@@ -1828,7 +1829,8 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
 					force_close_spend_delay: channel.get_counterparty_selected_contest_delay(),
 					is_outbound: channel.is_outbound(),
 					is_funding_locked: channel.is_usable(),
-					is_usable: channel.is_live(),
+					is_outbound_usable: channel.is_live(),
+					is_inbound_usable: channel.is_live(),
 					is_public: channel.should_announce(),
 				});
 			}
@@ -1861,6 +1863,19 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
 		self.list_channels_with_filter(|&(_, ref channel)| channel.is_live())
 	}
 
+	/// Gets the list of channels on which we can receive a payment to us, in random order. Useful
+	/// to generate a list of route hints when generating an invoice.
+	///
+	/// These are guaranteed to have their [`ChannelDetails::is_receivable`] value set to true, see the
+	/// documentation for [`ChannelDetails::is_receivable`] for more info on exactly what the criteria
+	/// are.
+	pub fn list_receivable_channels(&self) -> Vec<ChannelDetails> {
+		// Note we use is_live here instead of usable which leads to somewhat confused
+		// internal/external nomenclature, but that's ok cause that's probably what the user
+		// really wanted anyway.
+		self.list_channels_with_filter(|&(_, ref channel)| channel.is_receivable())
+	}
+
 	/// Helper function that issues the channel close events
 	fn issue_channel_close_events(&self, channel: &Channel<Signer>, closure_reason: ClosureReason) {
 		let mut pending_events_lock = self.pending_events.lock().unwrap();