Expand the Route object to include multiple paths.
[rust-lightning] / lightning / src / ln / channelmanager.rs
index 1afce1f7bb99e3b9ebe207567caeb205108b59f8..d1395e1271c3d5bc130d53c2cb29e561d4dc7f16 100644 (file)
@@ -30,7 +30,7 @@ use chain::transaction::OutPoint;
 use ln::channel::{Channel, ChannelError};
 use ln::channelmonitor::{ChannelMonitor, ChannelMonitorUpdate, ChannelMonitorUpdateErr, ManyChannelMonitor, CLTV_CLAIM_BUFFER, LATENCY_GRACE_PERIOD_BLOCKS, ANTI_REORG_DELAY};
 use ln::features::{InitFeatures, NodeFeatures};
-use ln::router::Route;
+use ln::router::{Route, RouteHop};
 use ln::msgs;
 use ln::onion_utils;
 use ln::msgs::{ChannelMessageHandler, DecodeError, LightningError};
@@ -68,12 +68,22 @@ use std::ops::Deref;
 // Alternatively, we can fill an outbound HTLC with a HTLCSource::OutboundRoute indicating this is
 // our payment, which we can use to decode errors or inform the user that the payment was sent.
 
+#[derive(Clone)] // See Channel::revoke_and_ack for why, tl;dr: Rust bug
+enum PendingHTLCRouting {
+       Forward {
+               onion_packet: msgs::OnionPacket,
+               short_channel_id: u64, // This should be NonZero<u64> eventually when we bump MSRV
+       },
+       Receive {
+               payment_data: Option<msgs::FinalOnionHopData>,
+       },
+}
+
 #[derive(Clone)] // See Channel::revoke_and_ack for why, tl;dr: Rust bug
 pub(super) struct PendingHTLCInfo {
-       onion_packet: Option<msgs::OnionPacket>,
+       routing: PendingHTLCRouting,
        incoming_shared_secret: [u8; 32],
        payment_hash: PaymentHash,
-       short_channel_id: u64,
        pub(super) amt_to_forward: u64,
        pub(super) outgoing_cltv_value: u32,
 }
@@ -111,12 +121,22 @@ pub(super) struct HTLCPreviousHopData {
        incoming_packet_shared_secret: [u8; 32],
 }
 
+struct ClaimableHTLC {
+       prev_hop: HTLCPreviousHopData,
+       value: u64,
+       /// Filled in when the HTLC was received with a payment_secret packet, which contains a
+       /// total_msat (which may differ from value if this is a Multi-Path Payment) and a
+       /// payment_secret which prevents path-probing attacks and can associate different HTLCs which
+       /// are part of the same payment.
+       payment_data: Option<msgs::FinalOnionHopData>,
+}
+
 /// Tracks the inbound corresponding to an outbound HTLC
 #[derive(Clone, PartialEq)]
 pub(super) enum HTLCSource {
        PreviousHopData(HTLCPreviousHopData),
        OutboundRoute {
-               route: Route,
+               path: Vec<RouteHop>,
                session_priv: SecretKey,
                /// Technically we can recalculate this from the route, but we cache it here to avoid
                /// doing a double-pass on route when we get a failure back
@@ -127,7 +147,7 @@ pub(super) enum HTLCSource {
 impl HTLCSource {
        pub fn dummy() -> Self {
                HTLCSource::OutboundRoute {
-                       route: Route { hops: Vec::new() },
+                       path: Vec::new(),
                        session_priv: SecretKey::from_slice(&[1; 32]).unwrap(),
                        first_hop_htlc_msat: 0,
                }
@@ -151,6 +171,9 @@ pub struct PaymentHash(pub [u8;32]);
 /// payment_preimage type, use to route payment between hop
 #[derive(Hash, Copy, Clone, PartialEq, Eq, Debug)]
 pub struct PaymentPreimage(pub [u8;32]);
+/// payment_secret type, use to authenticate sender to the receiver and tie MPP HTLCs together
+#[derive(Hash, Copy, Clone, PartialEq, Eq, Debug)]
+pub struct PaymentSecret(pub [u8;32]);
 
 type ShutdownResult = (Option<OutPoint>, ChannelMonitorUpdate, Vec<(HTLCSource, PaymentHash)>);
 
@@ -268,12 +291,14 @@ pub(super) struct ChannelHolder<ChanSigner: ChannelKeys> {
        /// guarantees are made about the existence of a channel with the short id here, nor the short
        /// ids in the PendingHTLCInfo!
        pub(super) forward_htlcs: HashMap<u64, Vec<HTLCForwardInfo>>,
-       /// payment_hash -> Vec<(amount_received, htlc_source)> for tracking things that were to us and
-       /// can be failed/claimed by the user
+       /// (payment_hash, payment_secret) -> Vec<HTLCs> for tracking HTLCs that
+       /// were to us and can be failed/claimed by the user
        /// Note that while this is held in the same mutex as the channels themselves, no consistency
        /// guarantees are made about the channels given here actually existing anymore by the time you
        /// go to read them!
-       pub(super) claimable_htlcs: HashMap<PaymentHash, Vec<(u64, HTLCPreviousHopData)>>,
+       /// TODO: We need to time out HTLCs sitting here which are waiting on other AMP HTLCs to
+       /// arrive.
+       claimable_htlcs: HashMap<(PaymentHash, Option<PaymentSecret>), Vec<ClaimableHTLC>>,
        /// Messages to send to peers - pushed to in the same lock that they are generated in (except
        /// for broadcast messages, where ordering isn't as strict).
        pub(super) pending_msg_events: Vec<events::MessageSendEvent>,
@@ -467,21 +492,41 @@ pub struct ChannelDetails {
 }
 
 macro_rules! handle_error {
-       ($self: ident, $internal: expr, $their_node_id: expr, $locked_channel_state: expr) => {
+       ($self: ident, $internal: expr, $their_node_id: expr) => {
                match $internal {
                        Ok(msg) => Ok(msg),
                        Err(MsgHandleErrInternal { err, shutdown_finish }) => {
+                               #[cfg(debug_assertions)]
+                               {
+                                       // In testing, ensure there are no deadlocks where the lock is already held upon
+                                       // entering the macro.
+                                       assert!($self.channel_state.try_lock().is_ok());
+                               }
+
+                               let mut msg_events = Vec::with_capacity(2);
+
                                if let Some((shutdown_res, update_option)) = shutdown_finish {
                                        $self.finish_force_close_channel(shutdown_res);
                                        if let Some(update) = update_option {
-                                               $locked_channel_state.pending_msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate {
+                                               msg_events.push(events::MessageSendEvent::BroadcastChannelUpdate {
                                                        msg: update
                                                });
                                        }
                                }
+
                                log_error!($self, "{}", err.err);
                                if let msgs::ErrorAction::IgnoreError = err.action {
-                               } else { $locked_channel_state.pending_msg_events.push(events::MessageSendEvent::HandleError { node_id: $their_node_id, action: err.action.clone() }); }
+                               } else {
+                                       msg_events.push(events::MessageSendEvent::HandleError {
+                                               node_id: $their_node_id,
+                                               action: err.action.clone()
+                                       });
+                               }
+
+                               if !msg_events.is_empty() {
+                                       $self.channel_state.lock().unwrap().pending_msg_events.append(&mut msg_events);
+                               }
+
                                // Return error in case higher-API need one
                                Err(err)
                        },
@@ -979,15 +1024,20 @@ impl<ChanSigner: ChannelKeys, M: Deref, T: Deref, K: Deref, F: Deref> ChannelMan
                                        return_err!("Upstream node set CLTV to the wrong value", 18, &byte_utils::be32_to_array(msg.cltv_expiry));
                                }
 
+                               let payment_data = match next_hop_data.format {
+                                       msgs::OnionHopDataFormat::Legacy { .. } => None,
+                                       msgs::OnionHopDataFormat::NonFinalNode { .. } => return_err!("Got non final data with an HMAC of 0", 0x4000 | 22, &[0;0]),
+                                       msgs::OnionHopDataFormat::FinalNode { payment_data } => payment_data,
+                               };
+
                                // Note that we could obviously respond immediately with an update_fulfill_htlc
                                // message, however that would leak that we are the recipient of this payment, so
                                // instead we stay symmetric with the forwarding case, only responding (after a
                                // delay) once they've send us a commitment_signed!
 
                                PendingHTLCStatus::Forward(PendingHTLCInfo {
-                                       onion_packet: None,
+                                       routing: PendingHTLCRouting::Receive { payment_data },
                                        payment_hash: msg.payment_hash.clone(),
-                                       short_channel_id: 0,
                                        incoming_shared_secret: shared_secret,
                                        amt_to_forward: next_hop_data.amt_to_forward,
                                        outgoing_cltv_value: next_hop_data.outgoing_cltv_value,
@@ -1031,15 +1081,17 @@ impl<ChanSigner: ChannelKeys, M: Deref, T: Deref, K: Deref, F: Deref> ChannelMan
                                let short_channel_id = match next_hop_data.format {
                                        msgs::OnionHopDataFormat::Legacy { short_channel_id } => short_channel_id,
                                        msgs::OnionHopDataFormat::NonFinalNode { short_channel_id } => short_channel_id,
-                                       msgs::OnionHopDataFormat::FinalNode => {
+                                       msgs::OnionHopDataFormat::FinalNode { .. } => {
                                                return_err!("Final Node OnionHopData provided for us as an intermediary node", 0x4000 | 22, &[0;0]);
                                        },
                                };
 
                                PendingHTLCStatus::Forward(PendingHTLCInfo {
-                                       onion_packet: Some(outgoing_packet),
+                                       routing: PendingHTLCRouting::Forward {
+                                               onion_packet: outgoing_packet,
+                                               short_channel_id: short_channel_id,
+                                       },
                                        payment_hash: msg.payment_hash.clone(),
-                                       short_channel_id: short_channel_id,
                                        incoming_shared_secret: shared_secret,
                                        amt_to_forward: next_hop_data.amt_to_forward,
                                        outgoing_cltv_value: next_hop_data.outgoing_cltv_value,
@@ -1047,8 +1099,11 @@ impl<ChanSigner: ChannelKeys, M: Deref, T: Deref, K: Deref, F: Deref> ChannelMan
                        };
 
                channel_state = Some(self.channel_state.lock().unwrap());
-               if let &PendingHTLCStatus::Forward(PendingHTLCInfo { ref onion_packet, ref short_channel_id, ref amt_to_forward, ref outgoing_cltv_value, .. }) = &pending_forward_info {
-                       if onion_packet.is_some() { // If short_channel_id is 0 here, we'll reject them in the body here
+               if let &PendingHTLCStatus::Forward(PendingHTLCInfo { ref routing, ref amt_to_forward, ref outgoing_cltv_value, .. }) = &pending_forward_info {
+                       // If short_channel_id is 0 here, we'll reject the HTLC as there cannot be a channel
+                       // with a short_channel_id of 0. This is important as various things later assume
+                       // short_channel_id is non-0 in any ::Forward.
+                       if let &PendingHTLCRouting::Forward { ref short_channel_id, .. } = routing {
                                let id_option = channel_state.as_ref().unwrap().short_to_id.get(&short_channel_id).cloned();
                                let forwarding_id = match id_option {
                                        None => { // unknown_next_peer
@@ -1166,14 +1221,26 @@ impl<ChanSigner: ChannelKeys, M: Deref, T: Deref, K: Deref, F: Deref> ChannelMan
        /// In case of APIError::MonitorUpdateFailed, the commitment update has been irrevocably
        /// committed on our end and we're just waiting for a monitor update to send it. Do NOT retry
        /// the payment via a different route unless you intend to pay twice!
-       pub fn send_payment(&self, route: Route, payment_hash: PaymentHash) -> Result<(), APIError> {
-               if route.hops.len() < 1 || route.hops.len() > 20 {
-                       return Err(APIError::RouteError{err: "Route didn't go anywhere/had bogus size"});
+       ///
+       /// payment_secret is unrelated to payment_hash (or PaymentPreimage) and exists to authenticate
+       /// the sender to the recipient and prevent payment-probing (deanonymization) attacks. For
+       /// newer nodes, it will be provided to you in the invoice. If you do not have one, the Route
+       /// must not contain multiple paths as multi-path payments require a recipient-provided
+       /// payment_secret.
+       /// If a payment_secret *is* provided, we assume that the invoice had the payment_secret feature
+       /// bit set (either as required or as available). If multiple paths are present in the Route,
+       /// we assume the invoice had the basic_mpp feature set.
+       pub fn send_payment(&self, route: Route, payment_hash: PaymentHash, payment_secret: &Option<PaymentSecret>) -> Result<(), APIError> {
+               if route.paths.len() < 1 || route.paths.len() > 1 {
+                       return Err(APIError::RouteError{err: "We currently don't support MPP, and we need at least one path"});
+               }
+               if route.paths[0].len() < 1 || route.paths[0].len() > 20 {
+                       return Err(APIError::RouteError{err: "Path didn't go anywhere/had bogus size"});
                }
                let our_node_id = self.get_our_node_id();
-               for (idx, hop) in route.hops.iter().enumerate() {
-                       if idx != route.hops.len() - 1 && hop.pubkey == our_node_id {
-                               return Err(APIError::RouteError{err: "Route went through us but wasn't a simple rebalance loop to us"});
+               for (idx, hop) in route.paths[0].iter().enumerate() {
+                       if idx != route.paths[0].len() - 1 && hop.pubkey == our_node_id {
+                               return Err(APIError::RouteError{err: "Path went through us but wasn't a simple rebalance loop to us"});
                        }
                }
 
@@ -1181,9 +1248,9 @@ impl<ChanSigner: ChannelKeys, M: Deref, T: Deref, K: Deref, F: Deref> ChannelMan
 
                let cur_height = self.latest_block_height.load(Ordering::Acquire) as u32 + 1;
 
-               let onion_keys = secp_call!(onion_utils::construct_onion_keys(&self.secp_ctx, &route, &session_priv),
+               let onion_keys = secp_call!(onion_utils::construct_onion_keys(&self.secp_ctx, &route.paths[0], &session_priv),
                                APIError::RouteError{err: "Pubkey along hop was maliciously selected"});
-               let (onion_payloads, htlc_msat, htlc_cltv) = onion_utils::build_onion_payloads(&route, cur_height)?;
+               let (onion_payloads, htlc_msat, htlc_cltv) = onion_utils::build_onion_payloads(&route.paths[0], payment_secret, cur_height)?;
                if onion_utils::route_size_insane(&onion_payloads) {
                        return Err(APIError::RouteError{err: "Route size too large considering onion data"});
                }
@@ -1191,10 +1258,9 @@ impl<ChanSigner: ChannelKeys, M: Deref, T: Deref, K: Deref, F: Deref> ChannelMan
 
                let _ = self.total_consistency_lock.read().unwrap();
 
-               let mut channel_lock = self.channel_state.lock().unwrap();
                let err: Result<(), _> = loop {
-
-                       let id = match channel_lock.short_to_id.get(&route.hops.first().unwrap().short_channel_id) {
+                       let mut channel_lock = self.channel_state.lock().unwrap();
+                       let id = match channel_lock.short_to_id.get(&route.paths[0].first().unwrap().short_channel_id) {
                                None => return Err(APIError::ChannelUnavailable{err: "No channel available with first hop!"}),
                                Some(id) => id.clone(),
                        };
@@ -1202,14 +1268,14 @@ impl<ChanSigner: ChannelKeys, M: Deref, T: Deref, K: Deref, F: Deref> ChannelMan
                        let channel_state = &mut *channel_lock;
                        if let hash_map::Entry::Occupied(mut chan) = channel_state.by_id.entry(id) {
                                match {
-                                       if chan.get().get_their_node_id() != route.hops.first().unwrap().pubkey {
+                                       if chan.get().get_their_node_id() != route.paths[0].first().unwrap().pubkey {
                                                return Err(APIError::RouteError{err: "Node ID mismatch on first hop!"});
                                        }
                                        if !chan.get().is_live() {
                                                return Err(APIError::ChannelUnavailable{err: "Peer for first hop currently disconnected/pending monitor update!"});
                                        }
                                        break_chan_entry!(self, chan.get_mut().send_htlc_and_commit(htlc_msat, payment_hash.clone(), htlc_cltv, HTLCSource::OutboundRoute {
-                                               route: route.clone(),
+                                               path: route.paths[0].clone(),
                                                session_priv: session_priv.clone(),
                                                first_hop_htlc_msat: htlc_msat,
                                        }, onion_packet), channel_state, chan)
@@ -1225,7 +1291,7 @@ impl<ChanSigner: ChannelKeys, M: Deref, T: Deref, K: Deref, F: Deref> ChannelMan
                                                }
 
                                                channel_state.pending_msg_events.push(events::MessageSendEvent::UpdateHTLCs {
-                                                       node_id: route.hops.first().unwrap().pubkey,
+                                                       node_id: route.paths[0].first().unwrap().pubkey,
                                                        updates: msgs::CommitmentUpdate {
                                                                update_add_htlcs: vec![update_add],
                                                                update_fulfill_htlcs: Vec::new(),
@@ -1242,7 +1308,7 @@ impl<ChanSigner: ChannelKeys, M: Deref, T: Deref, K: Deref, F: Deref> ChannelMan
                        return Ok(());
                };
 
-               match handle_error!(self, err, route.hops.first().unwrap().pubkey, channel_lock) {
+               match handle_error!(self, err, route.paths[0].first().unwrap().pubkey) {
                        Ok(_) => unreachable!(),
                        Err(e) => { Err(APIError::ChannelUnavailable { err: e.err }) }
                }
@@ -1261,8 +1327,7 @@ impl<ChanSigner: ChannelKeys, M: Deref, T: Deref, K: Deref, F: Deref> ChannelMan
                let _ = self.total_consistency_lock.read().unwrap();
 
                let (mut chan, msg, chan_monitor) = {
-                       let mut channel_state = self.channel_state.lock().unwrap();
-                       let (res, chan) = match channel_state.by_id.remove(temporary_channel_id) {
+                       let (res, chan) = match self.channel_state.lock().unwrap().by_id.remove(temporary_channel_id) {
                                Some(mut chan) => {
                                        (chan.get_outbound_funding_created(funding_txo)
                                                .map_err(|e| if let ChannelError::Close(msg) = e {
@@ -1272,7 +1337,7 @@ impl<ChanSigner: ChannelKeys, M: Deref, T: Deref, K: Deref, F: Deref> ChannelMan
                                },
                                None => return
                        };
-                       match handle_error!(self, res, chan.get_their_node_id(), channel_state) {
+                       match handle_error!(self, res, chan.get_their_node_id()) {
                                Ok(funding_msg) => {
                                        (chan, funding_msg.0, funding_msg.1)
                                },
@@ -1284,12 +1349,9 @@ impl<ChanSigner: ChannelKeys, M: Deref, T: Deref, K: Deref, F: Deref> ChannelMan
                if let Err(e) = self.monitor.add_monitor(chan_monitor.get_funding_txo().unwrap(), chan_monitor) {
                        match e {
                                ChannelMonitorUpdateErr::PermanentFailure => {
-                                       {
-                                               let mut channel_state = self.channel_state.lock().unwrap();
-                                               match handle_error!(self, Err(MsgHandleErrInternal::from_finish_shutdown("ChannelMonitor storage failure", *temporary_channel_id, chan.force_shutdown(true), None)), chan.get_their_node_id(), channel_state) {
-                                                       Err(_) => { return; },
-                                                       Ok(()) => unreachable!(),
-                                               }
+                                       match handle_error!(self, Err(MsgHandleErrInternal::from_finish_shutdown("ChannelMonitor storage failure", *temporary_channel_id, chan.force_shutdown(true), None)), chan.get_their_node_id()) {
+                                               Err(_) => { return; },
+                                               Ok(()) => unreachable!(),
                                        }
                                },
                                ChannelMonitorUpdateErr::TemporaryFailure => {
@@ -1417,7 +1479,9 @@ impl<ChanSigner: ChannelKeys, M: Deref, T: Deref, K: Deref, F: Deref> ChannelMan
                                                                                        htlc_id: prev_htlc_id,
                                                                                        incoming_packet_shared_secret: forward_info.incoming_shared_secret,
                                                                                });
-                                                                               failed_forwards.push((htlc_source, forward_info.payment_hash, 0x4000 | 10, None));
+                                                                               failed_forwards.push((htlc_source, forward_info.payment_hash,
+                                                                                       HTLCFailReason::Reason { failure_code: 0x4000 | 10, data: Vec::new() }
+                                                                               ));
                                                                        },
                                                                        HTLCForwardInfo::FailHTLC { .. } => {
                                                                                // Channel went away before we could fail it. This implies
@@ -1435,22 +1499,27 @@ impl<ChanSigner: ChannelKeys, M: Deref, T: Deref, K: Deref, F: Deref> ChannelMan
                                                let mut fail_htlc_msgs = Vec::new();
                                                for forward_info in pending_forwards.drain(..) {
                                                        match forward_info {
-                                                               HTLCForwardInfo::AddHTLC { prev_short_channel_id, prev_htlc_id, forward_info } => {
-                                                                       log_trace!(self, "Adding HTLC from short id {} with payment_hash {} to channel with short id {} after delay", log_bytes!(forward_info.payment_hash.0), prev_short_channel_id, short_chan_id);
+                                                               HTLCForwardInfo::AddHTLC { prev_short_channel_id, prev_htlc_id, forward_info: PendingHTLCInfo {
+                                                                               routing: PendingHTLCRouting::Forward {
+                                                                                       onion_packet, ..
+                                                                               }, incoming_shared_secret, payment_hash, amt_to_forward, outgoing_cltv_value }, } => {
+                                                                       log_trace!(self, "Adding HTLC from short id {} with payment_hash {} to channel with short id {} after delay", log_bytes!(payment_hash.0), prev_short_channel_id, short_chan_id);
                                                                        let htlc_source = HTLCSource::PreviousHopData(HTLCPreviousHopData {
                                                                                short_channel_id: prev_short_channel_id,
                                                                                htlc_id: prev_htlc_id,
-                                                                               incoming_packet_shared_secret: forward_info.incoming_shared_secret,
+                                                                               incoming_packet_shared_secret: incoming_shared_secret,
                                                                        });
-                                                                       match chan.get_mut().send_htlc(forward_info.amt_to_forward, forward_info.payment_hash, forward_info.outgoing_cltv_value, htlc_source.clone(), forward_info.onion_packet.unwrap()) {
+                                                                       match chan.get_mut().send_htlc(amt_to_forward, payment_hash, outgoing_cltv_value, htlc_source.clone(), onion_packet) {
                                                                                Err(e) => {
                                                                                        if let ChannelError::Ignore(msg) = e {
-                                                                                               log_trace!(self, "Failed to forward HTLC with payment_hash {}: {}", log_bytes!(forward_info.payment_hash.0), msg);
+                                                                                               log_trace!(self, "Failed to forward HTLC with payment_hash {}: {}", log_bytes!(payment_hash.0), msg);
                                                                                        } else {
                                                                                                panic!("Stated return value requirements in send_htlc() were not met");
                                                                                        }
                                                                                        let chan_update = self.get_channel_update(chan.get()).unwrap();
-                                                                                       failed_forwards.push((htlc_source, forward_info.payment_hash, 0x1000 | 7, Some(chan_update)));
+                                                                                       failed_forwards.push((htlc_source, payment_hash,
+                                                                                               HTLCFailReason::Reason { failure_code: 0x1000 | 7, data: chan_update.encode_with_len() }
+                                                                                       ));
                                                                                        continue;
                                                                                },
                                                                                Ok(update_add) => {
@@ -1469,6 +1538,9 @@ impl<ChanSigner: ChannelKeys, M: Deref, T: Deref, K: Deref, F: Deref> ChannelMan
                                                                                }
                                                                        }
                                                                },
+                                                               HTLCForwardInfo::AddHTLC { .. } => {
+                                                                       panic!("short_channel_id != 0 should imply any pending_forward entries are of type Forward");
+                                                               },
                                                                HTLCForwardInfo::FailHTLC { htlc_id, err_packet } => {
                                                                        log_trace!(self, "Failing HTLC back to channel with short id {} after delay", short_chan_id);
                                                                        match chan.get_mut().get_update_fail_htlc(htlc_id, err_packet) {
@@ -1520,10 +1592,8 @@ impl<ChanSigner: ChannelKeys, M: Deref, T: Deref, K: Deref, F: Deref> ChannelMan
                                                                                },
                                                                                ChannelError::CloseDelayBroadcast { .. } => { panic!("Wait is only generated on receipt of channel_reestablish, which is handled by try_chan_entry, we don't bother to support it here"); }
                                                                        };
-                                                                       match handle_error!(self, err, their_node_id, channel_state) {
-                                                                               Ok(_) => unreachable!(),
-                                                                               Err(_) => { continue; },
-                                                                       }
+                                                                       handle_errors.push((their_node_id, err));
+                                                                       continue;
                                                                }
                                                        };
                                                        if let Err(e) = self.monitor.update_monitor(chan.get().get_funding_txo().unwrap(), monitor_update) {
@@ -1548,20 +1618,60 @@ impl<ChanSigner: ChannelKeys, M: Deref, T: Deref, K: Deref, F: Deref> ChannelMan
                                } else {
                                        for forward_info in pending_forwards.drain(..) {
                                                match forward_info {
-                                                       HTLCForwardInfo::AddHTLC { prev_short_channel_id, prev_htlc_id, forward_info } => {
-                                                               let prev_hop_data = HTLCPreviousHopData {
+                                                       HTLCForwardInfo::AddHTLC { prev_short_channel_id, prev_htlc_id, forward_info: PendingHTLCInfo {
+                                                                       routing: PendingHTLCRouting::Receive { payment_data },
+                                                                       incoming_shared_secret, payment_hash, amt_to_forward, .. }, } => {
+                                                               let prev_hop = HTLCPreviousHopData {
                                                                        short_channel_id: prev_short_channel_id,
                                                                        htlc_id: prev_htlc_id,
-                                                                       incoming_packet_shared_secret: forward_info.incoming_shared_secret,
+                                                                       incoming_packet_shared_secret: incoming_shared_secret,
                                                                };
-                                                               match channel_state.claimable_htlcs.entry(forward_info.payment_hash) {
-                                                                       hash_map::Entry::Occupied(mut entry) => entry.get_mut().push((forward_info.amt_to_forward, prev_hop_data)),
-                                                                       hash_map::Entry::Vacant(entry) => { entry.insert(vec![(forward_info.amt_to_forward, prev_hop_data)]); },
-                                                               };
-                                                               new_events.push(events::Event::PaymentReceived {
-                                                                       payment_hash: forward_info.payment_hash,
-                                                                       amt: forward_info.amt_to_forward,
+
+                                                               let mut total_value = 0;
+                                                               let payment_secret_opt =
+                                                                       if let &Some(ref data) = &payment_data { Some(data.payment_secret.clone()) } else { None };
+                                                               let htlcs = channel_state.claimable_htlcs.entry((payment_hash, payment_secret_opt))
+                                                                       .or_insert(Vec::new());
+                                                               htlcs.push(ClaimableHTLC {
+                                                                       prev_hop,
+                                                                       value: amt_to_forward,
+                                                                       payment_data: payment_data.clone(),
                                                                });
+                                                               if let &Some(ref data) = &payment_data {
+                                                                       for htlc in htlcs.iter() {
+                                                                               total_value += htlc.value;
+                                                                               if htlc.payment_data.as_ref().unwrap().total_msat != data.total_msat {
+                                                                                       total_value = msgs::MAX_VALUE_MSAT;
+                                                                               }
+                                                                               if total_value >= msgs::MAX_VALUE_MSAT { break; }
+                                                                       }
+                                                                       if total_value >= msgs::MAX_VALUE_MSAT || total_value > data.total_msat  {
+                                                                               for htlc in htlcs.iter() {
+                                                                                       failed_forwards.push((HTLCSource::PreviousHopData(HTLCPreviousHopData {
+                                                                                                       short_channel_id: htlc.prev_hop.short_channel_id,
+                                                                                                       htlc_id: htlc.prev_hop.htlc_id,
+                                                                                                       incoming_packet_shared_secret: htlc.prev_hop.incoming_packet_shared_secret,
+                                                                                               }), payment_hash,
+                                                                                               HTLCFailReason::Reason { failure_code: 0x4000 | 15, data: byte_utils::be64_to_array(htlc.value).to_vec() }
+                                                                                       ));
+                                                                               }
+                                                                       } else if total_value == data.total_msat {
+                                                                               new_events.push(events::Event::PaymentReceived {
+                                                                                       payment_hash: payment_hash,
+                                                                                       payment_secret: Some(data.payment_secret),
+                                                                                       amt: total_value,
+                                                                               });
+                                                                       }
+                                                               } else {
+                                                                       new_events.push(events::Event::PaymentReceived {
+                                                                               payment_hash: payment_hash,
+                                                                               payment_secret: None,
+                                                                               amt: amt_to_forward,
+                                                                       });
+                                                               }
+                                                       },
+                                                       HTLCForwardInfo::AddHTLC { .. } => {
+                                                               panic!("short_channel_id == 0 should imply any pending_forward entries are of type Receive");
                                                        },
                                                        HTLCForwardInfo::FailHTLC { .. } => {
                                                                panic!("Got pending fail of our own HTLC");
@@ -1572,18 +1682,12 @@ impl<ChanSigner: ChannelKeys, M: Deref, T: Deref, K: Deref, F: Deref> ChannelMan
                        }
                }
 
-               for (htlc_source, payment_hash, failure_code, update) in failed_forwards.drain(..) {
-                       match update {
-                               None => self.fail_htlc_backwards_internal(self.channel_state.lock().unwrap(), htlc_source, &payment_hash, HTLCFailReason::Reason { failure_code, data: Vec::new() }),
-                               Some(chan_update) => self.fail_htlc_backwards_internal(self.channel_state.lock().unwrap(), htlc_source, &payment_hash, HTLCFailReason::Reason { failure_code, data: chan_update.encode_with_len() }),
-                       };
+               for (htlc_source, payment_hash, failure_reason) in failed_forwards.drain(..) {
+                       self.fail_htlc_backwards_internal(self.channel_state.lock().unwrap(), htlc_source, &payment_hash, failure_reason);
                }
 
-               if handle_errors.len() > 0 {
-                       let mut channel_state_lock = self.channel_state.lock().unwrap();
-                       for (their_node_id, err) in handle_errors.drain(..) {
-                               let _ = handle_error!(self, err, their_node_id, channel_state_lock);
-                       }
+               for (their_node_id, err) in handle_errors.drain(..) {
+                       let _ = handle_error!(self, err, their_node_id);
                }
 
                if new_events.is_empty() { return }
@@ -1621,17 +1725,17 @@ impl<ChanSigner: ChannelKeys, M: Deref, T: Deref, K: Deref, F: Deref> ChannelMan
        /// along the path (including in our own channel on which we received it).
        /// Returns false if no payment was found to fail backwards, true if the process of failing the
        /// HTLC backwards has been started.
-       pub fn fail_htlc_backwards(&self, payment_hash: &PaymentHash) -> bool {
+       pub fn fail_htlc_backwards(&self, payment_hash: &PaymentHash, payment_secret: &Option<PaymentSecret>) -> bool {
                let _ = self.total_consistency_lock.read().unwrap();
 
                let mut channel_state = Some(self.channel_state.lock().unwrap());
-               let removed_source = channel_state.as_mut().unwrap().claimable_htlcs.remove(payment_hash);
+               let removed_source = channel_state.as_mut().unwrap().claimable_htlcs.remove(&(*payment_hash, *payment_secret));
                if let Some(mut sources) = removed_source {
-                       for (recvd_value, htlc_with_hash) in sources.drain(..) {
+                       for htlc in sources.drain(..) {
                                if channel_state.is_none() { channel_state = Some(self.channel_state.lock().unwrap()); }
                                self.fail_htlc_backwards_internal(channel_state.take().unwrap(),
-                                               HTLCSource::PreviousHopData(htlc_with_hash), payment_hash,
-                                               HTLCFailReason::Reason { failure_code: 0x4000 | 15, data: byte_utils::be64_to_array(recvd_value).to_vec() });
+                                               HTLCSource::PreviousHopData(htlc.prev_hop), payment_hash,
+                                               HTLCFailReason::Reason { failure_code: 0x4000 | 15, data: byte_utils::be64_to_array(htlc.value).to_vec() });
                        }
                        true
                } else { false }
@@ -1649,7 +1753,7 @@ impl<ChanSigner: ChannelKeys, M: Deref, T: Deref, K: Deref, F: Deref> ChannelMan
                //between the branches here. We should make this async and move it into the forward HTLCs
                //timer handling.
                match source {
-                       HTLCSource::OutboundRoute { ref route, .. } => {
+                       HTLCSource::OutboundRoute { ref path, .. } => {
                                log_trace!(self, "Failing outbound payment HTLC with payment_hash {}", log_bytes!(payment_hash.0));
                                mem::drop(channel_state_lock);
                                match &onion_error {
@@ -1691,7 +1795,7 @@ impl<ChanSigner: ChannelKeys, M: Deref, T: Deref, K: Deref, F: Deref> ChannelMan
                                                self.pending_events.lock().unwrap().push(
                                                        events::Event::PaymentFailed {
                                                                payment_hash: payment_hash.clone(),
-                                                               rejected_by_dest: route.hops.len() == 1,
+                                                               rejected_by_dest: path.len() == 1,
 #[cfg(test)]
                                                                error_code: Some(*failure_code),
                                                        }
@@ -1747,28 +1851,39 @@ impl<ChanSigner: ChannelKeys, M: Deref, T: Deref, K: Deref, F: Deref> ChannelMan
        /// motivated attackers.
        ///
        /// May panic if called except in response to a PaymentReceived event.
-       pub fn claim_funds(&self, payment_preimage: PaymentPreimage, expected_amount: u64) -> bool {
+       pub fn claim_funds(&self, payment_preimage: PaymentPreimage, payment_secret: &Option<PaymentSecret>, expected_amount: u64) -> bool {
                let payment_hash = PaymentHash(Sha256::hash(&payment_preimage.0).into_inner());
 
                let _ = self.total_consistency_lock.read().unwrap();
 
                let mut channel_state = Some(self.channel_state.lock().unwrap());
-               let removed_source = channel_state.as_mut().unwrap().claimable_htlcs.remove(&payment_hash);
+               let removed_source = channel_state.as_mut().unwrap().claimable_htlcs.remove(&(payment_hash, *payment_secret));
                if let Some(mut sources) = removed_source {
-                       for (received_amount, htlc_with_hash) in sources.drain(..) {
+                       assert!(!sources.is_empty());
+                       let valid_mpp_amount = if let &Some(ref data) = &sources[0].payment_data {
+                               assert!(payment_secret.is_some());
+                               data.total_msat == expected_amount
+                       } else {
+                               assert!(payment_secret.is_none());
+                               false
+                       };
+
+                       let mut claimed_any_htlcs = false;
+                       for htlc in sources.drain(..) {
                                if channel_state.is_none() { channel_state = Some(self.channel_state.lock().unwrap()); }
-                               if received_amount < expected_amount || received_amount > expected_amount * 2 {
-                                       let mut htlc_msat_data = byte_utils::be64_to_array(received_amount).to_vec();
+                               if !valid_mpp_amount && (htlc.value < expected_amount || htlc.value > expected_amount * 2) {
+                                       let mut htlc_msat_data = byte_utils::be64_to_array(htlc.value).to_vec();
                                        let mut height_data = byte_utils::be32_to_array(self.latest_block_height.load(Ordering::Acquire) as u32).to_vec();
                                        htlc_msat_data.append(&mut height_data);
                                        self.fail_htlc_backwards_internal(channel_state.take().unwrap(),
-                                                                        HTLCSource::PreviousHopData(htlc_with_hash), &payment_hash,
+                                                                        HTLCSource::PreviousHopData(htlc.prev_hop), &payment_hash,
                                                                         HTLCFailReason::Reason { failure_code: 0x4000|15, data: htlc_msat_data });
                                } else {
-                                       self.claim_funds_internal(channel_state.take().unwrap(), HTLCSource::PreviousHopData(htlc_with_hash), payment_preimage);
+                                       self.claim_funds_internal(channel_state.take().unwrap(), HTLCSource::PreviousHopData(htlc.prev_hop), payment_preimage);
+                                       claimed_any_htlcs = true;
                                }
                        }
-                       true
+                       claimed_any_htlcs
                } else { false }
        }
        fn claim_funds_internal(&self, mut channel_state_lock: MutexGuard<ChannelHolder<ChanSigner>>, source: HTLCSource, payment_preimage: PaymentPreimage) {
@@ -1835,7 +1950,8 @@ impl<ChanSigner: ChannelKeys, M: Deref, T: Deref, K: Deref, F: Deref> ChannelMan
                        return;
                };
 
-               let _ = handle_error!(self, err, their_node_id, channel_state_lock);
+               mem::drop(channel_state_lock);
+               let _ = handle_error!(self, err, their_node_id);
        }
 
        /// Gets the node_id held by this ChannelManager
@@ -2377,7 +2493,10 @@ impl<ChanSigner: ChannelKeys, M: Deref, T: Deref, K: Deref, F: Deref> ChannelMan
                                        forward_event = Some(Duration::from_millis(MIN_HTLC_RELAY_HOLDING_CELL_MILLIS))
                                }
                                for (forward_info, prev_htlc_id) in pending_forwards.drain(..) {
-                                       match channel_state.forward_htlcs.entry(forward_info.short_channel_id) {
+                                       match channel_state.forward_htlcs.entry(match forward_info.routing {
+                                                       PendingHTLCRouting::Forward { short_channel_id, .. } => short_channel_id,
+                                                       PendingHTLCRouting::Receive { .. } => 0,
+                                       }) {
                                                hash_map::Entry::Occupied(mut entry) => {
                                                        entry.get_mut().push(HTLCForwardInfo::AddHTLC { prev_short_channel_id, prev_htlc_id, forward_info });
                                                },
@@ -2579,9 +2698,9 @@ impl<ChanSigner: ChannelKeys, M: Deref, T: Deref, K: Deref, F: Deref> ChannelMan
        #[doc(hidden)]
        pub fn update_fee(&self, channel_id: [u8;32], feerate_per_kw: u64) -> Result<(), APIError> {
                let _ = self.total_consistency_lock.read().unwrap();
-               let mut channel_state_lock = self.channel_state.lock().unwrap();
                let their_node_id;
                let err: Result<(), _> = loop {
+                       let mut channel_state_lock = self.channel_state.lock().unwrap();
                        let channel_state = &mut *channel_state_lock;
 
                        match channel_state.by_id.entry(channel_id) {
@@ -2620,7 +2739,7 @@ impl<ChanSigner: ChannelKeys, M: Deref, T: Deref, K: Deref, F: Deref> ChannelMan
                        return Ok(())
                };
 
-               match handle_error!(self, err, their_node_id, channel_state_lock) {
+               match handle_error!(self, err, their_node_id) {
                        Ok(_) => unreachable!(),
                        Err(e) => { Err(APIError::APIMisuseError { err: e.err })}
                }
@@ -2830,146 +2949,82 @@ impl<ChanSigner: ChannelKeys, M: Deref + Sync + Send, T: Deref + Sync + Send, K:
 {
        fn handle_open_channel(&self, their_node_id: &PublicKey, their_features: InitFeatures, msg: &msgs::OpenChannel) {
                let _ = self.total_consistency_lock.read().unwrap();
-               let res = self.internal_open_channel(their_node_id, their_features, msg);
-               if res.is_err() {
-                       let mut channel_state_lock = self.channel_state.lock().unwrap();
-                       let _ = handle_error!(self, res, *their_node_id, channel_state_lock);
-               }
+               let _ = handle_error!(self, self.internal_open_channel(their_node_id, their_features, msg), *their_node_id);
        }
 
        fn handle_accept_channel(&self, their_node_id: &PublicKey, their_features: InitFeatures, msg: &msgs::AcceptChannel) {
                let _ = self.total_consistency_lock.read().unwrap();
-               let res = self.internal_accept_channel(their_node_id, their_features, msg);
-               if res.is_err() {
-                       let mut channel_state_lock = self.channel_state.lock().unwrap();
-                       let _ = handle_error!(self, res, *their_node_id, channel_state_lock);
-               }
+               let _ = handle_error!(self, self.internal_accept_channel(their_node_id, their_features, msg), *their_node_id);
        }
 
        fn handle_funding_created(&self, their_node_id: &PublicKey, msg: &msgs::FundingCreated) {
                let _ = self.total_consistency_lock.read().unwrap();
-               let res = self.internal_funding_created(their_node_id, msg);
-               if res.is_err() {
-                       let mut channel_state_lock = self.channel_state.lock().unwrap();
-                       let _ = handle_error!(self, res, *their_node_id, channel_state_lock);
-               }
+               let _ = handle_error!(self, self.internal_funding_created(their_node_id, msg), *their_node_id);
        }
 
        fn handle_funding_signed(&self, their_node_id: &PublicKey, msg: &msgs::FundingSigned) {
                let _ = self.total_consistency_lock.read().unwrap();
-               let res = self.internal_funding_signed(their_node_id, msg);
-               if res.is_err() {
-                       let mut channel_state_lock = self.channel_state.lock().unwrap();
-                       let _ = handle_error!(self, res, *their_node_id, channel_state_lock);
-               }
+               let _ = handle_error!(self, self.internal_funding_signed(their_node_id, msg), *their_node_id);
        }
 
        fn handle_funding_locked(&self, their_node_id: &PublicKey, msg: &msgs::FundingLocked) {
                let _ = self.total_consistency_lock.read().unwrap();
-               let res = self.internal_funding_locked(their_node_id, msg);
-               if res.is_err() {
-                       let mut channel_state_lock = self.channel_state.lock().unwrap();
-                       let _ = handle_error!(self, res, *their_node_id, channel_state_lock);
-               }
+               let _ = handle_error!(self, self.internal_funding_locked(their_node_id, msg), *their_node_id);
        }
 
        fn handle_shutdown(&self, their_node_id: &PublicKey, msg: &msgs::Shutdown) {
                let _ = self.total_consistency_lock.read().unwrap();
-               let res = self.internal_shutdown(their_node_id, msg);
-               if res.is_err() {
-                       let mut channel_state_lock = self.channel_state.lock().unwrap();
-                       let _ = handle_error!(self, res, *their_node_id, channel_state_lock);
-               }
+               let _ = handle_error!(self, self.internal_shutdown(their_node_id, msg), *their_node_id);
        }
 
        fn handle_closing_signed(&self, their_node_id: &PublicKey, msg: &msgs::ClosingSigned) {
                let _ = self.total_consistency_lock.read().unwrap();
-               let res = self.internal_closing_signed(their_node_id, msg);
-               if res.is_err() {
-                       let mut channel_state_lock = self.channel_state.lock().unwrap();
-                       let _ = handle_error!(self, res, *their_node_id, channel_state_lock);
-               }
+               let _ = handle_error!(self, self.internal_closing_signed(their_node_id, msg), *their_node_id);
        }
 
        fn handle_update_add_htlc(&self, their_node_id: &PublicKey, msg: &msgs::UpdateAddHTLC) {
                let _ = self.total_consistency_lock.read().unwrap();
-               let res = self.internal_update_add_htlc(their_node_id, msg);
-               if res.is_err() {
-                       let mut channel_state_lock = self.channel_state.lock().unwrap();
-                       let _ = handle_error!(self, res, *their_node_id, channel_state_lock);
-               }
+               let _ = handle_error!(self, self.internal_update_add_htlc(their_node_id, msg), *their_node_id);
        }
 
        fn handle_update_fulfill_htlc(&self, their_node_id: &PublicKey, msg: &msgs::UpdateFulfillHTLC) {
                let _ = self.total_consistency_lock.read().unwrap();
-               let res = self.internal_update_fulfill_htlc(their_node_id, msg);
-               if res.is_err() {
-                       let mut channel_state_lock = self.channel_state.lock().unwrap();
-                       let _ = handle_error!(self, res, *their_node_id, channel_state_lock);
-               }
+               let _ = handle_error!(self, self.internal_update_fulfill_htlc(their_node_id, msg), *their_node_id);
        }
 
        fn handle_update_fail_htlc(&self, their_node_id: &PublicKey, msg: &msgs::UpdateFailHTLC) {
                let _ = self.total_consistency_lock.read().unwrap();
-               let res = self.internal_update_fail_htlc(their_node_id, msg);
-               if res.is_err() {
-                       let mut channel_state_lock = self.channel_state.lock().unwrap();
-                       let _ = handle_error!(self, res, *their_node_id, channel_state_lock);
-               }
+               let _ = handle_error!(self, self.internal_update_fail_htlc(their_node_id, msg), *their_node_id);
        }
 
        fn handle_update_fail_malformed_htlc(&self, their_node_id: &PublicKey, msg: &msgs::UpdateFailMalformedHTLC) {
                let _ = self.total_consistency_lock.read().unwrap();
-               let res = self.internal_update_fail_malformed_htlc(their_node_id, msg);
-               if res.is_err() {
-                       let mut channel_state_lock = self.channel_state.lock().unwrap();
-                       let _ = handle_error!(self, res, *their_node_id, channel_state_lock);
-               }
+               let _ = handle_error!(self, self.internal_update_fail_malformed_htlc(their_node_id, msg), *their_node_id);
        }
 
        fn handle_commitment_signed(&self, their_node_id: &PublicKey, msg: &msgs::CommitmentSigned) {
                let _ = self.total_consistency_lock.read().unwrap();
-               let res = self.internal_commitment_signed(their_node_id, msg);
-               if res.is_err() {
-                       let mut channel_state_lock = self.channel_state.lock().unwrap();
-                       let _ = handle_error!(self, res, *their_node_id, channel_state_lock);
-               }
+               let _ = handle_error!(self, self.internal_commitment_signed(their_node_id, msg), *their_node_id);
        }
 
        fn handle_revoke_and_ack(&self, their_node_id: &PublicKey, msg: &msgs::RevokeAndACK) {
                let _ = self.total_consistency_lock.read().unwrap();
-               let res = self.internal_revoke_and_ack(their_node_id, msg);
-               if res.is_err() {
-                       let mut channel_state_lock = self.channel_state.lock().unwrap();
-                       let _ = handle_error!(self, res, *their_node_id, channel_state_lock);
-               }
+               let _ = handle_error!(self, self.internal_revoke_and_ack(their_node_id, msg), *their_node_id);
        }
 
        fn handle_update_fee(&self, their_node_id: &PublicKey, msg: &msgs::UpdateFee) {
                let _ = self.total_consistency_lock.read().unwrap();
-               let res = self.internal_update_fee(their_node_id, msg);
-               if res.is_err() {
-                       let mut channel_state_lock = self.channel_state.lock().unwrap();
-                       let _ = handle_error!(self, res, *their_node_id, channel_state_lock);
-               }
+               let _ = handle_error!(self, self.internal_update_fee(their_node_id, msg), *their_node_id);
        }
 
        fn handle_announcement_signatures(&self, their_node_id: &PublicKey, msg: &msgs::AnnouncementSignatures) {
                let _ = self.total_consistency_lock.read().unwrap();
-               let res = self.internal_announcement_signatures(their_node_id, msg);
-               if res.is_err() {
-                       let mut channel_state_lock = self.channel_state.lock().unwrap();
-                       let _ = handle_error!(self, res, *their_node_id, channel_state_lock);
-               }
+               let _ = handle_error!(self, self.internal_announcement_signatures(their_node_id, msg), *their_node_id);
        }
 
        fn handle_channel_reestablish(&self, their_node_id: &PublicKey, msg: &msgs::ChannelReestablish) {
                let _ = self.total_consistency_lock.read().unwrap();
-               let res = self.internal_channel_reestablish(their_node_id, msg);
-               if res.is_err() {
-                       let mut channel_state_lock = self.channel_state.lock().unwrap();
-                       let _ = handle_error!(self, res, *their_node_id, channel_state_lock);
-               }
+               let _ = handle_error!(self, self.internal_channel_reestablish(their_node_id, msg), *their_node_id);
        }
 
        fn peer_disconnected(&self, their_node_id: &PublicKey, no_connection_possible: bool) {
@@ -3119,10 +3174,19 @@ const MIN_SERIALIZATION_VERSION: u8 = 1;
 
 impl Writeable for PendingHTLCInfo {
        fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
-               self.onion_packet.write(writer)?;
+               match &self.routing {
+                       &PendingHTLCRouting::Forward { ref onion_packet, ref short_channel_id } => {
+                               0u8.write(writer)?;
+                               onion_packet.write(writer)?;
+                               short_channel_id.write(writer)?;
+                       },
+                       &PendingHTLCRouting::Receive { ref payment_data } => {
+                               1u8.write(writer)?;
+                               payment_data.write(writer)?;
+                       },
+               }
                self.incoming_shared_secret.write(writer)?;
                self.payment_hash.write(writer)?;
-               self.short_channel_id.write(writer)?;
                self.amt_to_forward.write(writer)?;
                self.outgoing_cltv_value.write(writer)?;
                Ok(())
@@ -3132,10 +3196,18 @@ impl Writeable for PendingHTLCInfo {
 impl Readable for PendingHTLCInfo {
        fn read<R: ::std::io::Read>(reader: &mut R) -> Result<PendingHTLCInfo, DecodeError> {
                Ok(PendingHTLCInfo {
-                       onion_packet: Readable::read(reader)?,
+                       routing: match Readable::read(reader)? {
+                               0u8 => PendingHTLCRouting::Forward {
+                                       onion_packet: Readable::read(reader)?,
+                                       short_channel_id: Readable::read(reader)?,
+                               },
+                               1u8 => PendingHTLCRouting::Receive {
+                                       payment_data: Readable::read(reader)?,
+                               },
+                               _ => return Err(DecodeError::InvalidValue),
+                       },
                        incoming_shared_secret: Readable::read(reader)?,
                        payment_hash: Readable::read(reader)?,
-                       short_channel_id: Readable::read(reader)?,
                        amt_to_forward: Readable::read(reader)?,
                        outgoing_cltv_value: Readable::read(reader)?,
                })
@@ -3200,6 +3272,12 @@ impl_writeable!(HTLCPreviousHopData, 0, {
        incoming_packet_shared_secret
 });
 
+impl_writeable!(ClaimableHTLC, 0, {
+       prev_hop,
+       value,
+       payment_data
+});
+
 impl Writeable for HTLCSource {
        fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
                match self {
@@ -3207,9 +3285,9 @@ impl Writeable for HTLCSource {
                                0u8.write(writer)?;
                                hop_data.write(writer)?;
                        },
-                       &HTLCSource::OutboundRoute { ref route, ref session_priv, ref first_hop_htlc_msat } => {
+                       &HTLCSource::OutboundRoute { ref path, ref session_priv, ref first_hop_htlc_msat } => {
                                1u8.write(writer)?;
-                               route.write(writer)?;
+                               path.write(writer)?;
                                session_priv.write(writer)?;
                                first_hop_htlc_msat.write(writer)?;
                        }
@@ -3223,7 +3301,7 @@ impl Readable for HTLCSource {
                match <u8 as Readable>::read(reader)? {
                        0 => Ok(HTLCSource::PreviousHopData(Readable::read(reader)?)),
                        1 => Ok(HTLCSource::OutboundRoute {
-                               route: Readable::read(reader)?,
+                               path: Readable::read(reader)?,
                                session_priv: Readable::read(reader)?,
                                first_hop_htlc_msat: Readable::read(reader)?,
                        }),
@@ -3341,9 +3419,8 @@ impl<ChanSigner: ChannelKeys + Writeable, M: Deref, T: Deref, K: Deref, F: Deref
                for (payment_hash, previous_hops) in channel_state.claimable_htlcs.iter() {
                        payment_hash.write(writer)?;
                        (previous_hops.len() as u64).write(writer)?;
-                       for &(recvd_amt, ref previous_hop) in previous_hops.iter() {
-                               recvd_amt.write(writer)?;
-                               previous_hop.write(writer)?;
+                       for htlc in previous_hops.iter() {
+                               htlc.write(writer)?;
                        }
                }
 
@@ -3520,7 +3597,7 @@ impl<'a, ChanSigner: ChannelKeys + Readable, M: Deref, T: Deref, K: Deref, F: De
                        let previous_hops_len: u64 = Readable::read(reader)?;
                        let mut previous_hops = Vec::with_capacity(cmp::min(previous_hops_len as usize, 2));
                        for _ in 0..previous_hops_len {
-                               previous_hops.push((Readable::read(reader)?, Readable::read(reader)?));
+                               previous_hops.push(Readable::read(reader)?);
                        }
                        claimable_htlcs.insert(payment_hash, previous_hops);
                }