Add MPP ID to pending_outbound_htlcs

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

Author: valentinewallace

lightning/src/ln/channelmanager.rs

@@ -491,8 +491,11 @@ pub struct ChannelManager<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref,
 	/// which may generate a claim event, we may receive similar duplicate claim/fail MonitorEvents
 	/// after reloading from disk while replaying blocks against ChannelMonitors.
 	///
+	/// Each payment has each of its MPP part's session_priv bytes in the HashSet of the map (even
+	/// payments over a single path).
+	///
 	/// Locked *after* channel_state.
-	pending_outbound_payments: Mutex<HashSet<[u8; 32]>>,
+	pending_outbound_payments: Mutex<HashMap<MppId, HashSet<[u8; 32]>>>,
 
 	our_network_key: SecretKey,
 	our_network_pubkey: PublicKey,
@@ -1156,7 +1159,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
 				pending_msg_events: Vec::new(),
 			}),
 			pending_inbound_payments: Mutex::new(HashMap::new()),
-			pending_outbound_payments: Mutex::new(HashSet::new()),
+			pending_outbound_payments: Mutex::new(HashMap::new()),
 
 			our_network_key: keys_manager.get_node_secret(),
 			our_network_pubkey: PublicKey::from_secret_key(&secp_ctx, &keys_manager.get_node_secret()),
@@ -1853,7 +1856,9 @@ 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));
+		let mut pending_outbounds = self.pending_outbound_payments.lock().unwrap();
+		let sessions = pending_outbounds.entry(mpp_id).or_insert(HashSet::new());
+		assert!(sessions.insert(session_priv_bytes));
 
 		let err: Result<(), _> = loop {
 			let mut channel_lock = self.channel_state.lock().unwrap();
@@ -2832,23 +2837,27 @@ 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, .. } => {
-					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_events.lock().unwrap().push(
-							events::Event::PaymentFailed {
-								payment_hash,
-								rejected_by_dest: false,
-								network_update: None,
-#[cfg(test)]
-								error_code: None,
-#[cfg(test)]
-								error_data: None,
+				HTLCSource::OutboundRoute { session_priv, mpp_id, .. } => {
+					let mut session_priv_bytes = [0; 32];
+					session_priv_bytes.copy_from_slice(&session_priv[..]);
+					let mut outbounds = self.pending_outbound_payments.lock().unwrap();
+					if let hash_map::Entry::Occupied(mut sessions) = outbounds.entry(mpp_id) {
+						if sessions.get_mut().remove(&session_priv_bytes) {
+							self.pending_events.lock().unwrap().push(
+								events::Event::PaymentFailed {
+									payment_hash,
+									rejected_by_dest: false,
+									network_update: None,
+									#[cfg(test)]
+									error_code: None,
+									#[cfg(test)]
+									error_data: None,
+								}
+							);
+							if sessions.get().len() == 0 {
+								sessions.remove();
 							}
-						)
+						}
 					} else {
 						log_trace!(self.logger, "Received duplicative fail for HTLC with payment_hash {}", log_bytes!(payment_hash.0));
 					}
@@ -2873,12 +2882,19 @@ 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, .. } => {
-				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)
-				} {
+			HTLCSource::OutboundRoute { ref path, session_priv, mpp_id, .. } => {
+				let mut session_priv_bytes = [0; 32];
+				session_priv_bytes.copy_from_slice(&session_priv[..]);
+				let mut outbounds = self.pending_outbound_payments.lock().unwrap();
+				if let hash_map::Entry::Occupied(mut sessions) = outbounds.entry(mpp_id) {
+					if !sessions.get_mut().remove(&session_priv_bytes) {
+						log_trace!(self.logger, "Received duplicative fail for HTLC with payment_hash {}", log_bytes!(payment_hash.0));
+						return;
+					}
+					if sessions.get().len() == 0 {
+						sessions.remove();
+					}
+				} else {
 					log_trace!(self.logger, "Received duplicative fail for HTLC with payment_hash {}", log_bytes!(payment_hash.0));
 					return;
 				}
@@ -3119,17 +3135,22 @@ 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)
-				} {
-					let mut pending_events = self.pending_events.lock().unwrap();
-					pending_events.push(events::Event::PaymentSent {
-						payment_preimage
-					});
+				let mut session_priv_bytes = [0; 32];
+				session_priv_bytes.copy_from_slice(&session_priv[..]);
+				let mut outbounds = self.pending_outbound_payments.lock().unwrap();
+				if let Some(sessions) = outbounds.get_mut(&mpp_id) {
+					if sessions.remove(&session_priv_bytes) {
+						self.pending_events.lock().unwrap().push(
+							events::Event::PaymentSent { payment_preimage }
+						);
+						if sessions.len() == 0 {
+							outbounds.remove(&mpp_id);
+						}
+					} else {
+						log_trace!(self.logger, "Received duplicative fulfill for HTLC with payment_preimage {}", log_bytes!(payment_preimage.0));
+					}
 				} else {
 					log_trace!(self.logger, "Received duplicative fulfill for HTLC with payment_preimage {}", log_bytes!(payment_preimage.0));
 				}
@@ -5105,12 +5126,21 @@ 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() {
-			session_priv.write(writer)?;
+		// For backwards compat, write the session privs and their total length.
+		let mut num_pending_outbounds_compat: u64 = 0;
+		for (_, outbounds) in pending_outbound_payments.iter() {
+			num_pending_outbounds_compat += outbounds.len() as u64;
+		}
+		num_pending_outbounds_compat.write(writer)?;
+		for (_, outbounds) in pending_outbound_payments.iter() {
+			for outbound in outbounds.iter() {
+				outbound.write(writer)?;
+			}
 		}
 
-		write_tlv_fields!(writer, {});
+		write_tlv_fields!(writer, {
+			(1, pending_outbound_payments, required),
+		});
 
 		Ok(())
 	}
@@ -5363,15 +5393,23 @@ 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));
-		for _ in 0..pending_outbound_payments_count {
-			if !pending_outbound_payments.insert(Readable::read(reader)?) {
-				return Err(DecodeError::InvalidValue);
-			}
+		let pending_outbound_payments_count_compat: u64 = Readable::read(reader)?;
+		let mut pending_outbound_payments_compat: HashMap<MppId, HashSet<[u8; 32]>> =
+			HashMap::with_capacity(cmp::min(pending_outbound_payments_count_compat as usize, MAX_ALLOC_SIZE/32));
+		for _ in 0..pending_outbound_payments_count_compat {
+			let session_priv = Readable::read(reader)?;
+			if pending_outbound_payments_compat.insert(MppId(session_priv), [session_priv].iter().cloned().collect()).is_some() {
+				return Err(DecodeError::InvalidValue)
+			};
 		}
 
-		read_tlv_fields!(reader, {});
+		let mut pending_outbound_payments = None;
+		read_tlv_fields!(reader, {
+			(1, pending_outbound_payments, option),
+		});
+		if pending_outbound_payments.is_none() {
+			pending_outbound_payments = Some(pending_outbound_payments_compat);
+		}
 
 		let mut secp_ctx = Secp256k1::new();
 		secp_ctx.seeded_randomize(&args.keys_manager.get_secure_random_bytes());
@@ -5392,7 +5430,7 @@ impl<'a, Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
 				pending_msg_events: Vec::new(),
 			}),
 			pending_inbound_payments: Mutex::new(pending_inbound_payments),
-			pending_outbound_payments: Mutex::new(pending_outbound_payments),
+			pending_outbound_payments: Mutex::new(pending_outbound_payments.unwrap()),
 
 			our_network_key: args.keys_manager.get_node_secret(),
 			our_network_pubkey: PublicKey::from_secret_key(&secp_ctx, &args.keys_manager.get_node_secret()),