Add attribution_data field to data structures

This commit does not yet introduce attribution data, but just adds the
field and required serialization logic to the relevant types.

Co-authored-by: Matt Corallo <git@bluematt.me>

Author: joostjager

fuzz/src/process_onion_failure.rs

@@ -118,7 +118,8 @@ fn do_test<Out: test_logger::Output>(data: &[u8], out: Out) {
 		HTLCSource::OutboundRoute { path, session_priv, first_hop_htlc_msat: 0, payment_id };
 
 	let failure_len = get_u16!();
-	let encrypted_packet = OnionErrorPacket { data: get_slice!(failure_len).into() };
+	let encrypted_packet =
+		OnionErrorPacket { data: get_slice!(failure_len).into(), attribution_data: None };
 
 	lightning::ln::process_onion_failure(&secp_ctx, &logger, &htlc_source, encrypted_packet);
 }

lightning/src/ln/channel.rs

@@ -50,7 +50,7 @@ use crate::ln::chan_utils::{
 #[cfg(splicing)]
 use crate::ln::chan_utils::FUNDING_TRANSACTION_WITNESS_WEIGHT;
 use crate::ln::chan_utils;
-use crate::ln::onion_utils::{HTLCFailReason};
+use crate::ln::onion_utils::{HTLCFailReason, AttributionData};
 use crate::chain::BestBlock;
 use crate::chain::chaininterface::{FeeEstimator, ConfirmationTarget, LowerBoundedFeeEstimator, fee_for_weight};
 use crate::chain::channelmonitor::{ChannelMonitor, ChannelMonitorUpdate, ChannelMonitorUpdateStep, LATENCY_GRACE_PERIOD_BLOCKS};
@@ -4907,7 +4907,7 @@ trait FailHTLCContents {
 impl FailHTLCContents for msgs::OnionErrorPacket {
 	type Message = msgs::UpdateFailHTLC;
 	fn to_message(self, htlc_id: u64, channel_id: ChannelId) -> Self::Message {
-		msgs::UpdateFailHTLC { htlc_id, channel_id, reason: self.data }
+		msgs::UpdateFailHTLC { htlc_id, channel_id, reason: self.data, attribution_data: self.attribution_data }
 	}
 	fn to_inbound_htlc_state(self) -> InboundHTLCState {
 		InboundHTLCState::LocalRemoved(InboundHTLCRemovalReason::FailRelay(self))
@@ -6821,6 +6821,7 @@ impl<SP: Deref> FundedChannel<SP> where
 							channel_id: self.context.channel_id(),
 							htlc_id: htlc.htlc_id,
 							reason: err_packet.data.clone(),
+							attribution_data: err_packet.attribution_data.clone(),
 						});
 					},
 					&InboundHTLCRemovalReason::FailMalformed((ref sha256_of_onion, ref failure_code)) => {
@@ -10225,6 +10226,7 @@ impl<SP: Deref> Writeable for FundedChannel<SP> where SP::Target: SignerProvider
 				dropped_inbound_htlcs += 1;
 			}
 		}
+		let mut removed_htlc_failure_attribution_data: Vec<&Option<AttributionData>> = Vec::new();
 		(self.context.pending_inbound_htlcs.len() as u64 - dropped_inbound_htlcs).write(writer)?;
 		for htlc in self.context.pending_inbound_htlcs.iter() {
 			if let &InboundHTLCState::RemoteAnnounced(_) = &htlc.state {
@@ -10250,9 +10252,10 @@ impl<SP: Deref> Writeable for FundedChannel<SP> where SP::Target: SignerProvider
 				&InboundHTLCState::LocalRemoved(ref removal_reason) => {
 					4u8.write(writer)?;
 					match removal_reason {
-						InboundHTLCRemovalReason::FailRelay(msgs::OnionErrorPacket { data }) => {
+						InboundHTLCRemovalReason::FailRelay(msgs::OnionErrorPacket { data, attribution_data }) => {
 							0u8.write(writer)?;
 							data.write(writer)?;
+							removed_htlc_failure_attribution_data.push(&attribution_data);
 						},
 						InboundHTLCRemovalReason::FailMalformed((hash, code)) => {
 							1u8.write(writer)?;
@@ -10312,11 +10315,13 @@ impl<SP: Deref> Writeable for FundedChannel<SP> where SP::Target: SignerProvider
 			pending_outbound_blinding_points.push(htlc.blinding_point);
 		}
 
-		let mut holding_cell_skimmed_fees: Vec<Option<u64>> = Vec::new();
-		let mut holding_cell_blinding_points: Vec<Option<PublicKey>> = Vec::new();
+		let holding_cell_htlc_update_count = self.context.holding_cell_htlc_updates.len();
+		let mut holding_cell_skimmed_fees: Vec<Option<u64>> = Vec::with_capacity(holding_cell_htlc_update_count);
+		let mut holding_cell_blinding_points: Vec<Option<PublicKey>> = Vec::with_capacity(holding_cell_htlc_update_count);
+		let mut holding_cell_failure_attribution_data: Vec<Option<&AttributionData>> = Vec::with_capacity(holding_cell_htlc_update_count);
 		// Vec of (htlc_id, failure_code, sha256_of_onion)
 		let mut malformed_htlcs: Vec<(u64, u16, [u8; 32])> = Vec::new();
-		(self.context.holding_cell_htlc_updates.len() as u64).write(writer)?;
+		(holding_cell_htlc_update_count as u64).write(writer)?;
 		for update in self.context.holding_cell_htlc_updates.iter() {
 			match update {
 				&HTLCUpdateAwaitingACK::AddHTLC {
@@ -10342,6 +10347,9 @@ impl<SP: Deref> Writeable for FundedChannel<SP> where SP::Target: SignerProvider
 					2u8.write(writer)?;
 					htlc_id.write(writer)?;
 					err_packet.data.write(writer)?;
+
+					// Store the attribution data for later writing.
+					holding_cell_failure_attribution_data.push(err_packet.attribution_data.as_ref());
 				}
 				&HTLCUpdateAwaitingACK::FailMalformedHTLC {
 					htlc_id, failure_code, sha256_of_onion
@@ -10353,6 +10361,10 @@ impl<SP: Deref> Writeable for FundedChannel<SP> where SP::Target: SignerProvider
 					2u8.write(writer)?;
 					htlc_id.write(writer)?;
 					Vec::<u8>::new().write(writer)?;
+
+					// Push 'None' attribution data for FailMalformedHTLC, because FailMalformedHTLC uses the same
+					// type 2 and is deserialized as a FailHTLC.
+					holding_cell_failure_attribution_data.push(None);
 				}
 			}
 		}
@@ -10525,6 +10537,8 @@ impl<SP: Deref> Writeable for FundedChannel<SP> where SP::Target: SignerProvider
 			(49, self.context.local_initiated_shutdown, option), // Added in 0.0.122
 			(51, is_manual_broadcast, option), // Added in 0.0.124
 			(53, funding_tx_broadcast_safe_event_emitted, option), // Added in 0.0.124
+			(55, removed_htlc_failure_attribution_data, optional_vec), // Added in 0.2
+			(57, holding_cell_failure_attribution_data, optional_vec), // Added in 0.2
 		});
 
 		Ok(())
@@ -10602,6 +10616,7 @@ impl<'a, 'b, 'c, ES: Deref, SP: Deref> ReadableArgs<(&'a ES, &'b SP, &'c Channel
 						let reason = match <u8 as Readable>::read(reader)? {
 							0 => InboundHTLCRemovalReason::FailRelay(msgs::OnionErrorPacket {
 								data: Readable::read(reader)?,
+								attribution_data: None,
 							}),
 							1 => InboundHTLCRemovalReason::FailMalformed(Readable::read(reader)?),
 							2 => InboundHTLCRemovalReason::Fulfill(Readable::read(reader)?),
@@ -10666,6 +10681,7 @@ impl<'a, 'b, 'c, ES: Deref, SP: Deref> ReadableArgs<(&'a ES, &'b SP, &'c Channel
 					htlc_id: Readable::read(reader)?,
 					err_packet: OnionErrorPacket {
 						data: Readable::read(reader)?,
+						attribution_data: None,
 					},
 				},
 				_ => return Err(DecodeError::InvalidValue),
@@ -10809,6 +10825,9 @@ impl<'a, 'b, 'c, ES: Deref, SP: Deref> ReadableArgs<(&'a ES, &'b SP, &'c Channel
 		let mut pending_outbound_blinding_points_opt: Option<Vec<Option<PublicKey>>> = None;
 		let mut holding_cell_blinding_points_opt: Option<Vec<Option<PublicKey>>> = None;
 
+		let mut removed_htlc_failure_attribution_data: Option<Vec<Option<AttributionData>>> = None;
+		let mut holding_cell_failure_attribution_data: Option<Vec<Option<AttributionData>>> = None;
+
 		let mut malformed_htlcs: Option<Vec<(u64, u16, [u8; 32])>> = None;
 		let mut monitor_pending_update_adds: Option<Vec<msgs::UpdateAddHTLC>> = None;
 
@@ -10851,6 +10870,8 @@ impl<'a, 'b, 'c, ES: Deref, SP: Deref> ReadableArgs<(&'a ES, &'b SP, &'c Channel
 			(49, local_initiated_shutdown, option),
 			(51, is_manual_broadcast, option),
 			(53, funding_tx_broadcast_safe_event_emitted, option),
+			(55, removed_htlc_failure_attribution_data, optional_vec),
+			(57, holding_cell_failure_attribution_data, optional_vec),
 		});
 
 		let holder_signer = signer_provider.derive_channel_signer(channel_keys_id);
@@ -10932,6 +10953,38 @@ impl<'a, 'b, 'c, ES: Deref, SP: Deref> ReadableArgs<(&'a ES, &'b SP, &'c Channel
 			if iter.next().is_some() { return Err(DecodeError::InvalidValue) }
 		}
 
+		if let Some(attribution_data_list) = removed_htlc_failure_attribution_data {
+			let mut removed_htlc_relay_failures =
+				pending_inbound_htlcs.iter_mut().filter_map(|status|
+					if let InboundHTLCState::LocalRemoved(InboundHTLCRemovalReason::FailRelay(ref mut packet)) = &mut status.state {
+						Some(&mut packet.attribution_data)
+					} else {
+						None
+					}
+				);
+
+			for attribution_data in attribution_data_list {
+				*removed_htlc_relay_failures.next().ok_or(DecodeError::InvalidValue)? = attribution_data;
+			}
+			if removed_htlc_relay_failures.next().is_some() { return Err(DecodeError::InvalidValue); }
+		}
+
+		if let Some(attribution_data_list) = holding_cell_failure_attribution_data {
+			let mut holding_cell_failures =
+				holding_cell_htlc_updates.iter_mut().filter_map(|upd|
+					if let HTLCUpdateAwaitingACK::FailHTLC { err_packet: OnionErrorPacket { ref mut attribution_data, .. }, .. } = upd {
+						Some(attribution_data)
+					} else {
+						None
+					}
+				);
+
+			for attribution_data in attribution_data_list {
+				*holding_cell_failures.next().ok_or(DecodeError::InvalidValue)? = attribution_data;
+			}
+			if holding_cell_failures.next().is_some() { return Err(DecodeError::InvalidValue); }
+		}
+
 		if let Some(malformed_htlcs) = malformed_htlcs {
 			for (malformed_htlc_id, failure_code, sha256_of_onion) in malformed_htlcs {
 				let htlc_idx = holding_cell_htlc_updates.iter().position(|htlc| {
@@ -11135,7 +11188,7 @@ mod tests {
 	use bitcoin::network::Network;
 	#[cfg(splicing)]
 	use bitcoin::Weight;
-	use crate::ln::onion_utils::INVALID_ONION_BLINDING;
+	use crate::ln::onion_utils::{AttributionData, INVALID_ONION_BLINDING};
 	use crate::types::payment::{PaymentHash, PaymentPreimage};
 	use crate::ln::channel_keys::{RevocationKey, RevocationBasepoint};
 	use crate::ln::channelmanager::{self, HTLCSource, PaymentId};
@@ -11772,7 +11825,7 @@ mod tests {
 			htlc_id: 0,
 		};
 		let dummy_holding_cell_failed_htlc = |htlc_id| HTLCUpdateAwaitingACK::FailHTLC {
-			htlc_id, err_packet: msgs::OnionErrorPacket { data: vec![42] }
+			htlc_id, err_packet: msgs::OnionErrorPacket { data: vec![42], attribution_data: Some(AttributionData::new()) }
 		};
 		let dummy_holding_cell_malformed_htlc = |htlc_id| HTLCUpdateAwaitingACK::FailMalformedHTLC {
 			htlc_id, failure_code: INVALID_ONION_BLINDING, sha256_of_onion: [0; 32],

lightning/src/ln/channelmanager.rs

@@ -59,7 +59,7 @@ use crate::types::features::Bolt11InvoiceFeatures;
 use crate::routing::router::{BlindedTail, InFlightHtlcs, Path, Payee, PaymentParameters, RouteParameters, RouteParametersConfig, Router, FixedRouter, Route};
 use crate::ln::onion_payment::{check_incoming_htlc_cltv, create_recv_pending_htlc_info, create_fwd_pending_htlc_info, decode_incoming_update_add_htlc_onion, HopConnector, InboundHTLCErr, NextPacketDetails};
 use crate::ln::msgs;
-use crate::ln::onion_utils;
+use crate::ln::onion_utils::{self};
 use crate::ln::onion_utils::{HTLCFailReason, INVALID_ONION_BLINDING};
 use crate::ln::msgs::{BaseMessageHandler, ChannelMessageHandler, CommitmentUpdate, DecodeError, LightningError, MessageSendEvent};
 #[cfg(test)]
@@ -4481,6 +4481,7 @@ where
 			channel_id: msg.channel_id,
 			htlc_id: msg.htlc_id,
 			reason: failure.data,
+			attribution_data: failure.attribution_data,
 		})
 	}
 
@@ -4510,6 +4511,7 @@ where
 						channel_id: msg.channel_id,
 						htlc_id: msg.htlc_id,
 						reason: failure.data,
+						attribution_data: failure.attribution_data,
 					}));
 				}
 			}
@@ -12924,11 +12926,15 @@ impl_writeable_tlv_based!(PendingHTLCInfo, {
 impl Writeable for HTLCFailureMsg {
 	fn write<W: Writer>(&self, writer: &mut W) -> Result<(), io::Error> {
 		match self {
-			HTLCFailureMsg::Relay(msgs::UpdateFailHTLC { channel_id, htlc_id, reason }) => {
+			HTLCFailureMsg::Relay(msgs::UpdateFailHTLC { channel_id, htlc_id, reason, attribution_data }) => {
 				0u8.write(writer)?;
 				channel_id.write(writer)?;
 				htlc_id.write(writer)?;
 				reason.write(writer)?;
+
+				// This code will only ever be hit for legacy data that is re-serialized. It isn't necessary to try
+				// writing out attribution data, because it can never be present.
+				debug_assert!(attribution_data.is_none());
 			},
 			HTLCFailureMsg::Malformed(msgs::UpdateFailMalformedHTLC {
 				channel_id, htlc_id, sha256_of_onion, failure_code
@@ -12953,6 +12959,7 @@ impl Readable for HTLCFailureMsg {
 					channel_id: Readable::read(reader)?,
 					htlc_id: Readable::read(reader)?,
 					reason: Readable::read(reader)?,
+					attribution_data: None,
 				}))
 			},
 			1 => {
@@ -13183,6 +13190,7 @@ impl Writeable for HTLCForwardInfo {
 				write_tlv_fields!(w, {
 					(0, htlc_id, required),
 					(2, err_packet.data, required),
+					(5, err_packet.attribution_data, option),
 				});
 			},
 			Self::FailMalformedHTLC { htlc_id, failure_code, sha256_of_onion } => {
@@ -13213,8 +13221,12 @@ impl Readable for HTLCForwardInfo {
 					(1, malformed_htlc_failure_code, option),
 					(2, err_packet, required),
 					(3, sha256_of_onion, option),
+					(5, attribution_data, option),
 				});
 				if let Some(failure_code) = malformed_htlc_failure_code {
+					if attribution_data.is_some() {
+						return Err(DecodeError::InvalidValue);
+					}
 					Self::FailMalformedHTLC {
 						htlc_id: _init_tlv_based_struct_field!(htlc_id, required),
 						failure_code,
@@ -13225,6 +13237,7 @@ impl Readable for HTLCForwardInfo {
 						htlc_id: _init_tlv_based_struct_field!(htlc_id, required),
 						err_packet: crate::ln::msgs::OnionErrorPacket {
 							data: _init_tlv_based_struct_field!(err_packet, required),
+							attribution_data: _init_tlv_based_struct_field!(attribution_data, option),
 						},
 					}
 				}
@@ -14910,6 +14923,7 @@ mod tests {
 	use bitcoin::secp256k1::ecdh::SharedSecret;
 	use core::sync::atomic::Ordering;
 	use crate::events::{Event, HTLCDestination, ClosureReason};
+	use crate::ln::onion_utils::AttributionData;
 	use crate::ln::types::ChannelId;
 	use crate::types::payment::{PaymentPreimage, PaymentHash, PaymentSecret};
 	use crate::ln::channelmanager::{create_recv_pending_htlc_info, inbound_payment, ChannelConfigOverrides, HTLCForwardInfo, InterceptId, PaymentId, RecipientOnionFields};
@@ -16232,7 +16246,7 @@ mod tests {
 		let mut nodes = create_network(1, &node_cfg, &chanmgrs);
 
 		let dummy_failed_htlc = |htlc_id| {
-			HTLCForwardInfo::FailHTLC { htlc_id, err_packet: msgs::OnionErrorPacket { data: vec![42] } }
+			HTLCForwardInfo::FailHTLC { htlc_id, err_packet: msgs::OnionErrorPacket { data: vec![42], attribution_data: Some(AttributionData::new()) } }
 		};
 		let dummy_malformed_htlc = |htlc_id| {
 			HTLCForwardInfo::FailMalformedHTLC { htlc_id, failure_code: 0x4000, sha256_of_onion: [0; 32] }

lightning/src/ln/functional_tests.rs

@@ -7114,6 +7114,7 @@ pub fn test_update_fulfill_htlc_bolt2_update_fail_htlc_before_commitment() {
 		channel_id: chan.2,
 		htlc_id: 0,
 		reason: Vec::new(),
+		attribution_data: None,
 	};
 
 	nodes[0].node.handle_update_fail_htlc(nodes[1].node.get_our_node_id(), &update_msg);

lightning/src/ln/msgs.rs

@@ -766,8 +766,10 @@ pub struct UpdateFailHTLC {
 	/// The HTLC ID
 	pub htlc_id: u64,
 	pub(crate) reason: Vec<u8>,
-}
 
+	/// Optional field for the attribution data that allows the sender to pinpoint the failing node under all conditions
+	pub attribution_data: Option<AttributionData>
+}
 /// An [`update_fail_malformed_htlc`] message to be sent to or received from a peer.
 ///
 /// [`update_fail_malformed_htlc`]: https://github.com/lightning/bolts/blob/master/02-peer-protocol.md#removing-an-htlc-update_fulfill_htlc-update_fail_htlc-and-update_fail_malformed_htlc
@@ -2056,6 +2058,7 @@ pub struct FinalOnionHopData {
 mod fuzzy_internal_msgs {
 	use bitcoin::secp256k1::PublicKey;
 	use crate::blinded_path::payment::{BlindedPaymentPath, PaymentConstraints, PaymentContext, PaymentRelay};
+	use crate::ln::onion_utils::AttributionData;
 	use crate::offers::invoice_request::InvoiceRequest;
 	use crate::types::payment::{PaymentPreimage, PaymentSecret};
 	use crate::types::features::{BlindedHopFeatures, Bolt12InvoiceFeatures};
@@ -2249,13 +2252,16 @@ mod fuzzy_internal_msgs {
 		// This really should be a constant size slice, but the spec lets these things be up to 128KB?
 		// (TODO) We limit it in decode to much lower...
 		pub data: Vec<u8>,
+		pub attribution_data: Option<AttributionData>,
 	}
 }
 #[cfg(fuzzing)]
 pub use self::fuzzy_internal_msgs::*;
 #[cfg(not(fuzzing))]
 pub(crate) use self::fuzzy_internal_msgs::*;
 
+use super::onion_utils::AttributionData;
+
 /// BOLT 4 onion packet including hop data for the next peer.
 #[derive(Clone, Hash, PartialEq, Eq)]
 pub struct OnionPacket {
@@ -2362,6 +2368,7 @@ impl From<UpdateFailHTLC> for OnionErrorPacket {
 	fn from(msg: UpdateFailHTLC) -> Self {
 		OnionErrorPacket {
 			data: msg.reason,
+			attribution_data: msg.attribution_data,
 		}
 	}
 }
@@ -2984,7 +2991,10 @@ impl_writeable_msg!(UpdateFailHTLC, {
 	channel_id,
 	htlc_id,
 	reason
-}, {});
+}, {
+	// Specified TLV key 1 plus 100 during testing phase.
+	(101, attribution_data, option)
+});
 
 impl_writeable_msg!(UpdateFailMalformedHTLC, {
 	channel_id,
@@ -3959,6 +3969,7 @@ impl_writeable_msg!(GossipTimestampFilter, {
 mod tests {
 	use bitcoin::{Amount, Transaction, TxIn, ScriptBuf, Sequence, Witness, TxOut};
 	use bitcoin::hex::DisplayHex;
+	use crate::ln::onion_utils::{AttributionData, HMAC_COUNT, HMAC_LEN, HOLD_TIME_LEN, MAX_HOPS};
 	use crate::ln::types::ChannelId;
 	use crate::types::payment::{PaymentPreimage, PaymentHash, PaymentSecret};
 	use crate::types::features::{ChannelFeatures, ChannelTypeFeatures, InitFeatures, NodeFeatures};
@@ -4964,10 +4975,14 @@ mod tests {
 		let update_fail_htlc = msgs::UpdateFailHTLC {
 			channel_id: ChannelId::from_bytes([2; 32]),
 			htlc_id: 2316138423780173,
-			reason: [1; 32].to_vec()
+			reason: [1; 32].to_vec(),
+			attribution_data: Some(AttributionData {
+				hold_times: [3; MAX_HOPS * HOLD_TIME_LEN],
+				hmacs: [3; HMAC_LEN * HMAC_COUNT],
+			})
 		};
 		let encoded_value = update_fail_htlc.encode();
-		let target_value = <Vec<u8>>::from_hex("020202020202020202020202020202020202020202020202020202020202020200083a840000034d00200101010101010101010101010101010101010101010101010101010101010101").unwrap();
+		let target_value = <Vec<u8>>::from_hex("020202020202020202020202020202020202020202020202020202020202020200083a840000034d0020010101010101010101010101010101010101010101010101010101010101010165fd03980303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303030303").unwrap();
 		assert_eq!(encoded_value, target_value);
 	}
 

lightning/src/ln/onion_payment.rs

@@ -534,6 +534,7 @@ where
 			channel_id: msg.channel_id,
 			htlc_id: msg.htlc_id,
 			reason: failure.data,
+			attribution_data: failure.attribution_data,
 		}));
 	};