From: Valentine Wallace <vwallace@protonmail.com>
Date: Thu, 26 Oct 2023 21:14:40 +0000 (-0400)
Subject: Store whether a received HTLC is blinded in PendingHTLCInfo
X-Git-Tag: v0.0.119~9^2~21
X-Git-Url: http://git.bitcoin.ninja/index.cgi?a=commitdiff_plain;h=339f3fccf80c8ccfc8de936df8de65481586f833;p=rust-lightning

Store whether a received HTLC is blinded in PendingHTLCInfo

Useful for knowing to fail back these HTLCs with malformed and
invalid_onion_blinding error per the BOLT 4 spec.
---

diff --git a/lightning/src/ln/channelmanager.rs b/lightning/src/ln/channelmanager.rs
index f1dae2747..b925d842e 100644
--- a/lightning/src/ln/channelmanager.rs
+++ b/lightning/src/ln/channelmanager.rs
@@ -155,6 +155,8 @@ pub enum PendingHTLCRouting {
 		/// [`Event::PaymentClaimable::onion_fields`] as
 		/// [`RecipientOnionFields::custom_tlvs`].
 		custom_tlvs: Vec<(u64, Vec<u8>)>,
+		/// Set if this HTLC is the final hop in a multi-hop blinded path.
+		requires_blinded_error: bool,
 	},
 	/// The onion indicates that this is for payment to us but which contains the preimage for
 	/// claiming included, and is unrelated to any invoice we'd previously generated (aka a
@@ -4398,7 +4400,10 @@ where
 							}) => {
 								let blinded_failure = routing.blinded_failure();
 								let (cltv_expiry, onion_payload, payment_data, phantom_shared_secret, mut onion_fields) = match routing {
-									PendingHTLCRouting::Receive { payment_data, payment_metadata, incoming_cltv_expiry, phantom_shared_secret, custom_tlvs } => {
+									PendingHTLCRouting::Receive {
+										payment_data, payment_metadata, incoming_cltv_expiry, phantom_shared_secret,
+										custom_tlvs, requires_blinded_error: _
+									} => {
 										let _legacy_hop_data = Some(payment_data.clone());
 										let onion_fields = RecipientOnionFields { payment_secret: Some(payment_data.payment_secret),
 												payment_metadata, custom_tlvs };
@@ -9374,6 +9379,7 @@ impl_writeable_tlv_based_enum!(PendingHTLCRouting,
 		(2, incoming_cltv_expiry, required),
 		(3, payment_metadata, option),
 		(5, custom_tlvs, optional_vec),
+		(7, requires_blinded_error, (default_value, false)),
 	},
 	(2, ReceiveKeysend) => {
 		(0, payment_preimage, required),
diff --git a/lightning/src/ln/onion_payment.rs b/lightning/src/ln/onion_payment.rs
index 5f03b86e0..5ea07cfab 100644
--- a/lightning/src/ln/onion_payment.rs
+++ b/lightning/src/ln/onion_payment.rs
@@ -112,16 +112,21 @@ pub(super) fn create_recv_pending_htlc_info(
 	amt_msat: u64, cltv_expiry: u32, phantom_shared_secret: Option<[u8; 32]>, allow_underpay: bool,
 	counterparty_skimmed_fee_msat: Option<u64>, current_height: u32, accept_mpp_keysend: bool,
 ) -> Result<PendingHTLCInfo, InboundOnionErr> {
-	let (payment_data, keysend_preimage, custom_tlvs, onion_amt_msat, outgoing_cltv_value, payment_metadata) = match hop_data {
+	let (
+		payment_data, keysend_preimage, custom_tlvs, onion_amt_msat, outgoing_cltv_value,
+		payment_metadata, requires_blinded_error
+	) = match hop_data {
 		msgs::InboundOnionPayload::Receive {
 			payment_data, keysend_preimage, custom_tlvs, amt_msat, outgoing_cltv_value, payment_metadata, ..
 		} =>
-			(payment_data, keysend_preimage, custom_tlvs, amt_msat, outgoing_cltv_value, payment_metadata),
+			(payment_data, keysend_preimage, custom_tlvs, amt_msat, outgoing_cltv_value, payment_metadata,
+			 false),
 		msgs::InboundOnionPayload::BlindedReceive {
-			amt_msat, total_msat, outgoing_cltv_value, payment_secret, ..
+			amt_msat, total_msat, outgoing_cltv_value, payment_secret, intro_node_blinding_point, ..
 		} => {
 			let payment_data = msgs::FinalOnionHopData { payment_secret, total_msat };
-			(Some(payment_data), None, Vec::new(), amt_msat, outgoing_cltv_value, None)
+			(Some(payment_data), None, Vec::new(), amt_msat, outgoing_cltv_value, None,
+			 intro_node_blinding_point.is_none())
 		}
 		msgs::InboundOnionPayload::Forward { .. } => {
 			return Err(InboundOnionErr {
@@ -208,6 +213,7 @@ pub(super) fn create_recv_pending_htlc_info(
 			incoming_cltv_expiry: outgoing_cltv_value,
 			phantom_shared_secret,
 			custom_tlvs,
+			requires_blinded_error,
 		}
 	} else {
 		return Err(InboundOnionErr {