Add MPP ID to pending_outbound_htlcs

We'll use this to correlate MPP shards in upcoming commits

lightning/src/ln/channelmanager.rs

@@ -490,7 +490,7 @@ pub struct ChannelManager<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref,
 	/// after reloading from disk while replaying blocks against ChannelMonitors.
 	///
 	/// Locked *after* channel_state.
-	pending_outbound_payments: Mutex<HashSet<[u8; 32]>>,
+	pending_outbound_payments: Mutex<HashSet<([u8; 32], Option<MppId>)>>,
 
 	our_network_key: SecretKey,
 	our_network_pubkey: PublicKey,
@@ -1807,7 +1807,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
 		let onion_packet = onion_utils::construct_onion_packet(onion_payloads, onion_keys, prng_seed, payment_hash);
 
 		let _persistence_guard = PersistenceNotifierGuard::notify_on_drop(&self.total_consistency_lock, &self.persistence_notifier);
-		assert!(self.pending_outbound_payments.lock().unwrap().insert(session_priv_bytes));
+		assert!(self.pending_outbound_payments.lock().unwrap().insert((session_priv_bytes, mpp_id)));
 
 		let err: Result<(), _> = loop {
 			let mut channel_lock = self.channel_state.lock().unwrap();
@@ -2676,11 +2676,11 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
 					self.fail_htlc_backwards_internal(channel_state,
 						htlc_src, &payment_hash, HTLCFailReason::Reason { failure_code, data: onion_failure_data});
 				},
-				HTLCSource::OutboundRoute { session_priv, .. } => {
+				HTLCSource::OutboundRoute { session_priv, mpp_id, .. } => {
 					if {
 						let mut session_priv_bytes = [0; 32];
 						session_priv_bytes.copy_from_slice(&session_priv[..]);
-						self.pending_outbound_payments.lock().unwrap().remove(&session_priv_bytes)
+						self.pending_outbound_payments.lock().unwrap().remove(&(session_priv_bytes, mpp_id))
 					} {
 						self.pending_events.lock().unwrap().push(
 							events::Event::PaymentFailed {
@@ -2716,11 +2716,11 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
 		// from block_connected which may run during initialization prior to the chain_monitor
 		// being fully configured. See the docs for `ChannelManagerReadArgs` for more.
 		match source {
-			HTLCSource::OutboundRoute { ref path, session_priv, .. } => {
+			HTLCSource::OutboundRoute { ref path, session_priv, mpp_id, .. } => {
 				if {
 					let mut session_priv_bytes = [0; 32];
 					session_priv_bytes.copy_from_slice(&session_priv[..]);
-					!self.pending_outbound_payments.lock().unwrap().remove(&session_priv_bytes)
+					!self.pending_outbound_payments.lock().unwrap().remove(&(session_priv_bytes, mpp_id))
 				} {
 					log_trace!(self.logger, "Received duplicative fail for HTLC with payment_hash {}", log_bytes!(payment_hash.0));
 					return;
@@ -2967,12 +2967,12 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
 
 	fn claim_funds_internal(&self, mut channel_state_lock: MutexGuard<ChannelHolder<Signer>>, source: HTLCSource, payment_preimage: PaymentPreimage, forwarded_htlc_value_msat: Option<u64>, from_onchain: bool) {
 		match source {
-			HTLCSource::OutboundRoute { session_priv, .. } => {
+			HTLCSource::OutboundRoute { session_priv, mpp_id, .. } => {
 				mem::drop(channel_state_lock);
 				if {
 					let mut session_priv_bytes = [0; 32];
 					session_priv_bytes.copy_from_slice(&session_priv[..]);
-					self.pending_outbound_payments.lock().unwrap().remove(&session_priv_bytes)
+					self.pending_outbound_payments.lock().unwrap().remove(&(session_priv_bytes, mpp_id))
 				} {
 					let mut pending_events = self.pending_events.lock().unwrap();
 					pending_events.push(events::Event::PaymentSent {
@@ -4919,11 +4919,15 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> Writeable f
 
 		let pending_outbound_payments = self.pending_outbound_payments.lock().unwrap();
 		(pending_outbound_payments.len() as u64).write(writer)?;
-		for session_priv in pending_outbound_payments.iter() {
+		let mut pending_outbound_mpp_ids = Vec::new();
+		for (session_priv, mpp_id) in pending_outbound_payments.iter() {
 			session_priv.write(writer)?;
+			pending_outbound_mpp_ids.push(mpp_id);
 		}
 
-		write_tlv_fields!(writer, {});
+		write_tlv_fields!(writer, {
+			// (0, pending_outbound_mpp_ids, vec_type),
+		});
 
 		Ok(())
 	}
@@ -5177,14 +5181,35 @@ impl<'a, Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
 		}
 
 		let pending_outbound_payments_count: u64 = Readable::read(reader)?;
-		let mut pending_outbound_payments: HashSet<[u8; 32]> = HashSet::with_capacity(cmp::min(pending_outbound_payments_count as usize, MAX_ALLOC_SIZE/32));
+		let mut pending_outbound_payments: HashSet<([u8; 32], Option<MppId>)> = HashSet::with_capacity(cmp::min(pending_outbound_payments_count as usize, MAX_ALLOC_SIZE/32));
+		let mut pending_outbound_session_privs = Vec::new();
+
 		for _ in 0..pending_outbound_payments_count {
-			if !pending_outbound_payments.insert(Readable::read(reader)?) {
-				return Err(DecodeError::InvalidValue);
-			}
+			pending_outbound_session_privs.push(Readable::read(reader)?);
 		}
 
-		read_tlv_fields!(reader, {});
+		let mut pending_outbound_mpp_ids = Vec::new();
+		read_tlv_fields!(reader, {
+			// TODO: how to make this line work
+			// (0, pending_outbound_mpp_ids, vec_type),
+		});
+
+		if pending_outbound_mpp_ids.len() == pending_outbound_session_privs.len() {
+			for (session_priv, mpp_id) in pending_outbound_session_privs.iter().zip(
+				pending_outbound_mpp_ids.iter()) {
+				if !pending_outbound_payments.insert((*session_priv, *mpp_id)) {
+					return Err(DecodeError::InvalidValue)
+				}
+			}
+		} else if pending_outbound_mpp_ids.len() == 0 {
+			for session_priv in pending_outbound_session_privs.iter() {
+				if !pending_outbound_payments.insert((*session_priv, None)) {
+					return Err(DecodeError::InvalidValue);
+				}
+			}
+		} else {
+			return Err(DecodeError::InvalidValue);
+		}
 
 		let mut secp_ctx = Secp256k1::new();
 		secp_ctx.seeded_randomize(&args.keys_manager.get_secure_random_bytes());
@@ -5428,7 +5453,7 @@ mod tests {
 		expect_payment_failed!(nodes[0], our_payment_hash, true);
 
 		// Send the second half of the original MPP payment.
-		nodes[0].node.send_payment_along_path(&route.paths[0], &our_payment_hash, &Some(payment_secret), 200_000, cur_height, payment_id, &None).unwrap();
+		nodes[0].node.send_payment_along_path(&route.paths[0], &our_payment_hash, &Some(payment_secret), 200_000, cur_height, mpp_id, &None).unwrap();
 		check_added_monitors!(nodes[0], 1);
 		let mut events = nodes[0].node.get_and_clear_pending_msg_events();
 		assert_eq!(events.len(), 1);