Introduce user_custom_data

Author: shaavan

lightning/src/ln/channelmanager.rs

@@ -204,6 +204,12 @@ pub enum PendingHTLCRouting {
 		/// [`Event::PaymentClaimable::onion_fields`] as
 		/// [`RecipientOnionFields::sender_custom_tlvs`].
 		sender_custom_tlvs: Vec<(u64, Vec<u8>)>,
+		/// Custom TLVs set by the receiver in the blinded path used to reach them.
+		///
+		/// For HTLCs received by LDK, this will be exposed in
+		/// [`Event::PaymentClaimable::onion_fields`] as
+		/// [`RecipientOnionFields::user_custom_data`].
+		user_custom_data: Vec<u8>,
 		/// Set if this HTLC is the final hop in a multi-hop blinded path.
 		requires_blinded_error: bool,
 	},
@@ -234,6 +240,11 @@ pub enum PendingHTLCRouting {
 		/// For HTLCs received by LDK, these will ultimately bubble back up as
 		/// [`RecipientOnionFields::sender_custom_tlvs`].
 		sender_custom_tlvs: Vec<(u64, Vec<u8>)>,
+		/// Custom TLVs set by the receiver in the blinded path used to reach them.
+		///
+		/// For HTLCs received by LDK, these will ultimately bubble back up as
+		/// [`RecipientOnionFields::user_custom_data`].
+		user_custom_data: Vec<u8>,
 		/// Set if this HTLC is the final hop in a multi-hop blinded path.
 		requires_blinded_error: bool,
 		/// Set if we are receiving a keysend to a blinded path, meaning we created the
@@ -6039,24 +6050,25 @@ where
 									PendingHTLCRouting::Receive {
 										payment_data, payment_metadata, payment_context,
 										incoming_cltv_expiry, phantom_shared_secret, sender_custom_tlvs,
-										requires_blinded_error: _
+										user_custom_data, requires_blinded_error: _
 									} => {
 										let _legacy_hop_data = Some(payment_data.clone());
 										let onion_fields = RecipientOnionFields { payment_secret: Some(payment_data.payment_secret),
-												payment_metadata, sender_custom_tlvs };
+												payment_metadata, sender_custom_tlvs, user_custom_data };
 										(incoming_cltv_expiry, OnionPayload::Invoice { _legacy_hop_data },
 											Some(payment_data), payment_context, phantom_shared_secret, onion_fields,
 											true)
 									},
 									PendingHTLCRouting::ReceiveKeysend {
 										payment_data, payment_preimage, payment_metadata,
-										incoming_cltv_expiry, sender_custom_tlvs, requires_blinded_error: _,
-										has_recipient_created_payment_secret,
+										incoming_cltv_expiry, sender_custom_tlvs, user_custom_data,
+										requires_blinded_error: _, has_recipient_created_payment_secret,
 									} => {
 										let onion_fields = RecipientOnionFields {
 											payment_secret: payment_data.as_ref().map(|data| data.payment_secret),
 											payment_metadata,
 											sender_custom_tlvs,
+											user_custom_data
 										};
 										(incoming_cltv_expiry, OnionPayload::Spontaneous(payment_preimage),
 											payment_data, None, None, onion_fields, has_recipient_created_payment_secret)
@@ -12453,6 +12465,7 @@ impl_writeable_tlv_based_enum!(PendingHTLCRouting,
 		(5, sender_custom_tlvs, optional_vec),
 		(7, requires_blinded_error, (default_value, false)),
 		(9, payment_context, option),
+		(11, user_custom_data, optional_vec),
 	},
 	(2, ReceiveKeysend) => {
 		(0, payment_preimage, required),
@@ -12462,6 +12475,7 @@ impl_writeable_tlv_based_enum!(PendingHTLCRouting,
 		(4, payment_data, option), // Added in 0.0.116
 		(5, sender_custom_tlvs, optional_vec),
 		(7, has_recipient_created_payment_secret, (default_value, false)),
+		(9, user_custom_data, optional_vec),
 	},
 );
 
@@ -15469,7 +15483,7 @@ mod tests {
 			payment_data: Some(msgs::FinalOnionHopData {
 				payment_secret: PaymentSecret([0; 32]), total_msat: sender_intended_amt_msat,
 			}),
-			sender_custom_tlvs: Vec::new(),
+			sender_custom_tlvs: Vec::new(), user_custom_data: Vec::new(), 
 		};
 		// Check that if the amount we received + the penultimate hop extra fee is less than the sender
 		// intended amount, we fail the payment.
@@ -15491,7 +15505,7 @@ mod tests {
 			payment_data: Some(msgs::FinalOnionHopData {
 				payment_secret: PaymentSecret([0; 32]), total_msat: sender_intended_amt_msat,
 			}),
-			sender_custom_tlvs: Vec::new(),
+			sender_custom_tlvs: Vec::new(), user_custom_data: Vec::new(), 
 		};
 		let current_height: u32 = node[0].node.best_block.read().unwrap().height;
 		assert!(create_recv_pending_htlc_info(hop_data, [0; 32], PaymentHash([0; 32]),
@@ -15515,7 +15529,7 @@ mod tests {
 			payment_data: Some(msgs::FinalOnionHopData {
 				payment_secret: PaymentSecret([0; 32]), total_msat: 100,
 			}),
-			sender_custom_tlvs: Vec::new(),
+			sender_custom_tlvs: Vec::new(), user_custom_data: Vec::new(), 
 		}, [0; 32], PaymentHash([0; 32]), 100, 23, None, true, None, current_height);
 
 		// Should not return an error as this condition:

lightning/src/ln/functional_test_utils.rs

@@ -2646,6 +2646,7 @@ pub struct PassAlongPathArgs<'a, 'b, 'c, 'd> {
 	pub expected_preimage: Option<PaymentPreimage>,
 	pub is_probe: bool,
 	pub sender_custom_tlvs: Vec<(u64, Vec<u8>)>,
+	pub user_custom_data: Vec<u8>,
 	pub payment_metadata: Option<Vec<u8>>,
 	pub expected_failure: Option<HTLCDestination>,
 }
@@ -2658,7 +2659,7 @@ impl<'a, 'b, 'c, 'd> PassAlongPathArgs<'a, 'b, 'c, 'd> {
 		Self {
 			origin_node, expected_path, recv_value, payment_hash, payment_secret: None, event,
 			payment_claimable_expected: true, clear_recipient_events: true, expected_preimage: None,
-			is_probe: false, sender_custom_tlvs: Vec::new(), payment_metadata: None, expected_failure: None,
+			is_probe: false, sender_custom_tlvs: Vec::new(), user_custom_data: Vec::new(),  payment_metadata: None, expected_failure: None,
 		}
 	}
 	pub fn without_clearing_recipient_events(mut self) -> Self {
@@ -2701,7 +2702,7 @@ pub fn do_pass_along_path<'a, 'b, 'c>(args: PassAlongPathArgs) -> Option<Event>
 	let PassAlongPathArgs {
 		origin_node, expected_path, recv_value, payment_hash: our_payment_hash,
 		payment_secret: our_payment_secret, event: ev, payment_claimable_expected,
-		clear_recipient_events, expected_preimage, is_probe, sender_custom_tlvs, payment_metadata,
+		clear_recipient_events, expected_preimage, is_probe, sender_custom_tlvs, user_custom_data, payment_metadata,
 		expected_failure
 	} = args;
 
@@ -2736,6 +2737,7 @@ pub fn do_pass_along_path<'a, 'b, 'c>(args: PassAlongPathArgs) -> Option<Event>
 						assert_eq!(node.node.get_our_node_id(), receiver_node_id.unwrap());
 						assert!(onion_fields.is_some());
 						assert_eq!(onion_fields.as_ref().unwrap().sender_custom_tlvs, sender_custom_tlvs);
+						assert_eq!(onion_fields.as_ref().unwrap().user_custom_data, user_custom_data);
 						assert_eq!(onion_fields.as_ref().unwrap().payment_metadata, payment_metadata);
 						match &purpose {
 							PaymentPurpose::Bolt11InvoicePayment { payment_preimage, payment_secret, .. } => {
@@ -2855,6 +2857,7 @@ pub struct ClaimAlongRouteArgs<'a, 'b, 'c, 'd> {
 	pub skip_last: bool,
 	pub payment_preimage: PaymentPreimage,
 	pub sender_custom_tlvs: Vec<(u64, Vec<u8>)>,
+	pub user_custom_data: Vec<u8>,
 	// Allow forwarding nodes to have taken 1 msat more fee than expected based on the downstream
 	// fulfill amount.
 	//
@@ -2873,7 +2876,7 @@ impl<'a, 'b, 'c, 'd> ClaimAlongRouteArgs<'a, 'b, 'c, 'd> {
 		Self {
 			origin_node, expected_paths, expected_extra_fees: vec![0; expected_paths.len()],
 			expected_min_htlc_overpay: vec![0; expected_paths.len()], skip_last: false, payment_preimage,
-			allow_1_msat_fee_overpay: false, sender_custom_tlvs: vec![],
+			allow_1_msat_fee_overpay: false, sender_custom_tlvs: vec![], user_custom_data: vec![]
 		}
 	}
 	pub fn skip_last(mut self, skip_last: bool) -> Self {
@@ -2896,12 +2899,17 @@ impl<'a, 'b, 'c, 'd> ClaimAlongRouteArgs<'a, 'b, 'c, 'd> {
 		self.sender_custom_tlvs = sender_custom_tlvs;
 		self
 	}
+	pub fn with_user_custom_data(mut self, user_custom_data: Vec<u8>) -> Self {
+		self.user_custom_data = user_custom_data;
+		self
+	}
 }
 
 pub fn pass_claimed_payment_along_route(args: ClaimAlongRouteArgs) -> u64 {
 	let ClaimAlongRouteArgs {
 		origin_node, expected_paths, expected_extra_fees, expected_min_htlc_overpay, skip_last,
 		payment_preimage: our_payment_preimage, allow_1_msat_fee_overpay, sender_custom_tlvs,
+		user_custom_data
 	} = args;
 	let claim_event = expected_paths[0].last().unwrap().node.get_and_clear_pending_events();
 	assert_eq!(claim_event.len(), 1);
@@ -2939,6 +2947,7 @@ pub fn pass_claimed_payment_along_route(args: ClaimAlongRouteArgs) -> u64 {
 			assert_eq!(htlcs.len(), expected_paths.len());  // One per path.
 			assert_eq!(htlcs.iter().map(|h| h.value_msat).sum::<u64>(), amount_msat);
 			assert_eq!(onion_fields.as_ref().unwrap().sender_custom_tlvs, sender_custom_tlvs);
+			assert_eq!(onion_fields.as_ref().unwrap().user_custom_data, user_custom_data);
 			check_claimed_htlcs_match_route(origin_node, expected_paths, htlcs);
 			fwd_amt_msat = amount_msat;
 		}

lightning/src/ln/max_payment_path_len_tests.rs

@@ -61,6 +61,7 @@ fn large_payment_metadata() {
 		payment_metadata: None,
 		keysend_preimage: None,
 		sender_custom_tlvs: &Vec::new(),
+		user_custom_data: &Vec::new(),
 		sender_intended_htlc_amt_msat: MIN_FINAL_VALUE_ESTIMATE_WITH_OVERPAY,
 		cltv_expiry_height: nodes[0].best_block_info().1 + DEFAULT_MAX_TOTAL_CLTV_EXPIRY_DELTA,
 	}.serialized_length();
@@ -77,7 +78,7 @@ fn large_payment_metadata() {
 	let mut recipient_onion_max_md_size = RecipientOnionFields {
 		payment_secret: Some(payment_secret),
 		payment_metadata: Some(payment_metadata.clone()),
-		sender_custom_tlvs: Vec::new(),
+		sender_custom_tlvs: Vec::new(), user_custom_data: Vec::new(), 
 	};
 	nodes[0].node.send_payment(payment_hash, recipient_onion_max_md_size.clone(), PaymentId(payment_hash.0), route_0_1.route_params.clone().unwrap(), Retry::Attempts(0)).unwrap();
 	check_added_monitors!(nodes[0], 1);
@@ -125,7 +126,7 @@ fn large_payment_metadata() {
 	let mut recipient_onion_allows_2_hops = RecipientOnionFields {
 		payment_secret: Some(payment_secret_2),
 		payment_metadata: Some(vec![42; max_metadata_len - INTERMED_PAYLOAD_LEN_ESTIMATE]),
-		sender_custom_tlvs: Vec::new(),
+		sender_custom_tlvs: Vec::new(), user_custom_data: Vec::new(), 
 	};
 	let mut route_params_0_2 = route_0_2.route_params.clone().unwrap();
 	route_params_0_2.payment_params.max_path_length = 2;
@@ -190,7 +191,8 @@ fn one_hop_blinded_path_with_custom_tlv() {
 		intro_node_blinding_point: Some(blinded_path.blinding_point()),
 		keysend_preimage: None,
 		invoice_request: None,
-		sender_custom_tlvs: &Vec::new()
+		sender_custom_tlvs: &Vec::new(),
+		user_custom_data: &Vec::new()
 	}.serialized_length();
 	let max_custom_tlv_len = 1300
 		- crate::util::ser::BigSize(CUSTOM_TLV_TYPE).serialized_length() // custom TLV type