Add htcl min/max to CounterpartyForwardingInfo

Author: ViktorTigerstrom

lightning/src/ln/channel.rs

@@ -5384,10 +5384,16 @@ impl<Signer: Sign> Channel<Signer> {
 		if msg.contents.htlc_minimum_msat >= self.channel_value_satoshis * 1000 {
 			return Err(ChannelError::Close("Minimum htlc value is greater than channel value".to_string()));
 		}
+		let outbound_htlc_maximum_msat = match msg.contents.htlc_maximum_msat {
+			OptionalField::Present(htcl_max) => Some(htcl_max),
+			OptionalField::Absent => None
+		};
 		self.counterparty_forwarding_info = Some(CounterpartyForwardingInfo {
 			fee_base_msat: msg.contents.fee_base_msat,
 			fee_proportional_millionths: msg.contents.fee_proportional_millionths,
-			cltv_expiry_delta: msg.contents.cltv_expiry_delta
+			cltv_expiry_delta: msg.contents.cltv_expiry_delta,
+			outbound_htlc_minimum_msat: Some(msg.contents.htlc_minimum_msat),
+			outbound_htlc_maximum_msat,
 		});
 
 		Ok(())
@@ -5842,6 +5848,7 @@ impl<Signer: Sign> Writeable for Channel<Signer> {
 			(17, self.announcement_sigs_state, required),
 			(19, self.latest_inbound_scid_alias, option),
 			(21, self.outbound_scid_alias, required),
+			(23, self.counterparty_forwarding_info.as_ref().map(|info| info.outbound_htlc_maximum_msat).unwrap_or(None), option),
 		});
 
 		Ok(())
@@ -6040,12 +6047,14 @@ impl<'a, Signer: Sign, K: Deref> ReadableArgs<(&'a K, u32)> for Channel<Signer>
 			let _dummy: u32 = Readable::read(reader)?;
 		}
 
-		let counterparty_forwarding_info = match <u8 as Readable>::read(reader)? {
+		let mut counterparty_forwarding_info = match <u8 as Readable>::read(reader)? {
 			0 => None,
 			1 => Some(CounterpartyForwardingInfo {
 				fee_base_msat: Readable::read(reader)?,
 				fee_proportional_millionths: Readable::read(reader)?,
 				cltv_expiry_delta: Readable::read(reader)?,
+				outbound_htlc_minimum_msat: Some(counterparty_htlc_minimum_msat),
+				outbound_htlc_maximum_msat: None,
 			}),
 			_ => return Err(DecodeError::InvalidValue),
 		};
@@ -6099,6 +6108,7 @@ impl<'a, Signer: Sign, K: Deref> ReadableArgs<(&'a K, u32)> for Channel<Signer>
 		let mut announcement_sigs_state = Some(AnnouncementSigsState::NotSent);
 		let mut latest_inbound_scid_alias = None;
 		let mut outbound_scid_alias = None;
+		let mut outbound_htlc_maximum_msat = None;
 
 		read_tlv_fields!(reader, {
 			(0, announcement_sigs, option),
@@ -6116,8 +6126,14 @@ impl<'a, Signer: Sign, K: Deref> ReadableArgs<(&'a K, u32)> for Channel<Signer>
 			(17, announcement_sigs_state, option),
 			(19, latest_inbound_scid_alias, option),
 			(21, outbound_scid_alias, option),
+			(23, outbound_htlc_maximum_msat, option),
 		});
 
+		if outbound_htlc_maximum_msat.is_some() && counterparty_forwarding_info.is_some() {
+			let cf_info = counterparty_forwarding_info.as_mut().unwrap();
+			cf_info.outbound_htlc_maximum_msat = outbound_htlc_maximum_msat;
+		}
+
 		if let Some(preimages) = preimages_opt {
 			let mut iter = preimages.into_iter();
 			for htlc in pending_outbound_htlcs.iter_mut() {

lightning/src/ln/channelmanager.rs

@@ -1159,6 +1159,11 @@ pub struct CounterpartyForwardingInfo {
 	/// such that the outgoing HTLC is forwardable to this counterparty. See `msgs::ChannelUpdate`'s
 	/// `cltv_expiry_delta` for more details.
 	pub cltv_expiry_delta: u16,
+	/// The smallest value HTLC (in msat) the remote peer will accept, for this channel. This field
+	/// is only None for `CounterpartyForwardingInfo` objects serialized prior to LDK 0.0.107
+	pub outbound_htlc_minimum_msat: Option<u64>,
+	/// The largest value HTLC (in msat) the remote peer currently will accept, for this channel.
+	pub outbound_htlc_maximum_msat: Option<u64>,
 }
 
 /// Channel parameters which apply to our counterparty. These are split out from [`ChannelDetails`]
@@ -6055,6 +6060,8 @@ impl_writeable_tlv_based!(CounterpartyForwardingInfo, {
 	(2, fee_base_msat, required),
 	(4, fee_proportional_millionths, required),
 	(6, cltv_expiry_delta, required),
+	(7, outbound_htlc_minimum_msat, option),
+	(9, outbound_htlc_maximum_msat, option),
 });
 
 impl_writeable_tlv_based!(ChannelCounterparty, {