Split only-receive/forward data out of PendingHTLCInfo into an enum
[rust-lightning] / lightning / src / ln / channelmanager.rs
index 420d8e92fa498659b6b8ffa2c8afef798265fbb0..6b637bec348d1071527abacbed881e4ebfc46dc3 100644 (file)
@@ -30,7 +30,7 @@ use chain::transaction::OutPoint;
 use ln::channel::{Channel, ChannelError};
 use ln::channelmonitor::{ChannelMonitor, ChannelMonitorUpdateErr, ManyChannelMonitor, CLTV_CLAIM_BUFFER, LATENCY_GRACE_PERIOD_BLOCKS, ANTI_REORG_DELAY};
 use ln::router::Route;
-use ln::features::InitFeatures;
+use ln::features::{InitFeatures, NodeFeatures};
 use ln::msgs;
 use ln::onion_utils;
 use ln::msgs::{ChannelMessageHandler, DecodeError, LightningError};
@@ -57,19 +57,31 @@ use std::ops::Deref;
 // forward the HTLC with information it will give back to us when it does so, or if it should Fail
 // the HTLC with the relevant message for the Channel to handle giving to the remote peer.
 //
-// When a Channel forwards an HTLC to its peer, it will give us back the PendingForwardHTLCInfo
-// which we will use to construct an outbound HTLC, with a relevant HTLCSource::PreviousHopData
-// filled in to indicate where it came from (which we can use to either fail-backwards or fulfill
-// the HTLC backwards along the relevant path).
+// Once said HTLC is committed in the Channel, if the PendingHTLCStatus indicated Forward, the
+// Channel will return the PendingHTLCInfo back to us, and we will create an HTLCForwardInfo
+// with it to track where it came from (in case of onwards-forward error), waiting a random delay
+// before we forward it.
+//
+// We will then use HTLCForwardInfo's PendingHTLCInfo to construct an outbound HTLC, with a
+// relevant HTLCSource::PreviousHopData filled in to indicate where it came from (which we can use
+// to either fail-backwards or fulfill the HTLC backwards along the relevant path).
 // 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.
-/// Stores the info we will need to send when we want to forward an HTLC onwards
+
+#[derive(Clone)] // See Channel::revoke_and_ack for why, tl;dr: Rust bug
+enum PendingForwardReceiveHTLCInfo {
+       Forward {
+               onion_packet: msgs::OnionPacket,
+               short_channel_id: u64, // This should be NonZero<u64> eventually
+       },
+       Receive {},
+}
+
 #[derive(Clone)] // See Channel::revoke_and_ack for why, tl;dr: Rust bug
-pub(super) struct PendingForwardHTLCInfo {
-       onion_packet: Option<msgs::OnionPacket>,
+pub(super) struct PendingHTLCInfo {
+       type_data: PendingForwardReceiveHTLCInfo,
        incoming_shared_secret: [u8; 32],
        payment_hash: PaymentHash,
-       short_channel_id: u64,
        pub(super) amt_to_forward: u64,
        pub(super) outgoing_cltv_value: u32,
 }
@@ -83,10 +95,22 @@ pub(super) enum HTLCFailureMsg {
 /// Stores whether we can't forward an HTLC or relevant forwarding info
 #[derive(Clone)] // See Channel::revoke_and_ack for why, tl;dr: Rust bug
 pub(super) enum PendingHTLCStatus {
-       Forward(PendingForwardHTLCInfo),
+       Forward(PendingHTLCInfo),
        Fail(HTLCFailureMsg),
 }
 
+pub(super) enum HTLCForwardInfo {
+       AddHTLC {
+               prev_short_channel_id: u64,
+               prev_htlc_id: u64,
+               forward_info: PendingHTLCInfo,
+       },
+       FailHTLC {
+               htlc_id: u64,
+               err_packet: msgs::OnionErrorPacket,
+       },
+}
+
 /// Tracks the inbound corresponding to an outbound HTLC
 #[derive(Clone, PartialEq)]
 pub(super) struct HTLCPreviousHopData {
@@ -231,18 +255,6 @@ impl MsgHandleErrInternal {
 /// second to 30 seconds, but people expect lightning to be, you know, kinda fast, sadly.
 const MIN_HTLC_RELAY_HOLDING_CELL_MILLIS: u64 = 100;
 
-pub(super) enum HTLCForwardInfo {
-       AddHTLC {
-               prev_short_channel_id: u64,
-               prev_htlc_id: u64,
-               forward_info: PendingForwardHTLCInfo,
-       },
-       FailHTLC {
-               htlc_id: u64,
-               err_packet: msgs::OnionErrorPacket,
-       },
-}
-
 /// For events which result in both a RevokeAndACK and a CommitmentUpdate, by default they should
 /// be sent in the order they appear in the return value, however sometimes the order needs to be
 /// variable at runtime (eg Channel::channel_reestablish needs to re-send messages in the order
@@ -262,7 +274,7 @@ pub(super) struct ChannelHolder<ChanSigner: ChannelKeys> {
        /// short channel id -> forward infos. Key of 0 means payments received
        /// Note that while this is held in the same mutex as the channels themselves, no consistency
        /// guarantees are made about the existence of a channel with the short id here, nor the short
-       /// ids in the PendingForwardHTLCInfo!
+       /// 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
@@ -355,6 +367,8 @@ pub struct ChannelManager<ChanSigner: ChannelKeys, M: Deref> where M::Target: Ma
        channel_state: Mutex<ChannelHolder<ChanSigner>>,
        our_network_key: SecretKey,
 
+       last_node_announcement_serial: AtomicUsize,
+
        /// The bulk of our storage will eventually be here (channels and message queues and the like).
        /// If we are connected to a peer we always at least have an entry here, even if no channels
        /// are currently open with that peer.
@@ -571,7 +585,7 @@ macro_rules! handle_monitor_err {
                                                        } else if $resend_commitment { "commitment" }
                                                        else if $resend_raa { "RAA" }
                                                        else { "nothing" },
-                                               (&$failed_forwards as &Vec<(PendingForwardHTLCInfo, u64)>).len(),
+                                               (&$failed_forwards as &Vec<(PendingHTLCInfo, u64)>).len(),
                                                (&$failed_fails as &Vec<(HTLCSource, PaymentHash, HTLCFailReason)>).len());
                                if !$resend_commitment {
                                        debug_assert!($action_type == RAACommitmentOrder::RevokeAndACKFirst || !$resend_raa);
@@ -649,6 +663,8 @@ impl<ChanSigner: ChannelKeys, M: Deref> ChannelManager<ChanSigner, M> where M::T
                        }),
                        our_network_key: keys_manager.get_node_secret(),
 
+                       last_node_announcement_serial: AtomicUsize::new(0),
+
                        per_peer_state: RwLock::new(HashMap::new()),
 
                        pending_events: Mutex::new(Vec::new()),
@@ -910,6 +926,9 @@ impl<ChanSigner: ChannelKeys, M: Deref> ChannelManager<ChanSigner, M> where M::T
                                Err(err) => {
                                        let error_code = match err {
                                                msgs::DecodeError::UnknownVersion => 0x4000 | 1, // unknown realm byte
+                                               msgs::DecodeError::UnknownRequiredFeature|
+                                               msgs::DecodeError::InvalidValue|
+                                               msgs::DecodeError::ShortRead => 0x4000 | 22, // invalid_onion_payload
                                                _ => 0x2000 | 2, // Should never happen
                                        };
                                        return_err!("Unable to decode our hop data", error_code, &[0;0]);
@@ -917,7 +936,7 @@ impl<ChanSigner: ChannelKeys, M: Deref> ChannelManager<ChanSigner, M> where M::T
                                Ok(msg) => {
                                        let mut hmac = [0; 32];
                                        if let Err(_) = chacha_stream.read_exact(&mut hmac[..]) {
-                                               return_err!("Unable to decode hop data", 0x4000 | 1, &[0;0]);
+                                               return_err!("Unable to decode hop data", 0x4000 | 22, &[0;0]);
                                        }
                                        (msg, hmac)
                                },
@@ -960,10 +979,9 @@ impl<ChanSigner: ChannelKeys, M: Deref> ChannelManager<ChanSigner, M> where M::T
                                // instead we stay symmetric with the forwarding case, only responding (after a
                                // delay) once they've send us a commitment_signed!
 
-                               PendingHTLCStatus::Forward(PendingForwardHTLCInfo {
-                                       onion_packet: None,
+                               PendingHTLCStatus::Forward(PendingHTLCInfo {
+                                       type_data: PendingForwardReceiveHTLCInfo::Receive {},
                                        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,
@@ -971,6 +989,15 @@ impl<ChanSigner: ChannelKeys, M: Deref> ChannelManager<ChanSigner, M> where M::T
                        } else {
                                let mut new_packet_data = [0; 20*65];
                                let read_pos = chacha_stream.read(&mut new_packet_data).unwrap();
+                               #[cfg(debug_assertions)]
+                               {
+                                       // Check two things:
+                                       // a) that the behavior of our stream here will return Ok(0) even if the TLV
+                                       //    read above emptied out our buffer and the unwrap() wont needlessly panic
+                                       // b) that we didn't somehow magically end up with extra data.
+                                       let mut t = [0; 1];
+                                       debug_assert!(chacha_stream.read(&mut t).unwrap() == 0);
+                               }
                                // Once we've emptied the set of bytes our peer gave us, encrypt 0 bytes until we
                                // fill the onion hop data we'll forward to our next-hop peer.
                                chacha_stream.chacha.process_in_place(&mut new_packet_data[read_pos..]);
@@ -995,10 +1022,20 @@ impl<ChanSigner: ChannelKeys, M: Deref> ChannelManager<ChanSigner, M> where M::T
                                        hmac: next_hop_hmac.clone(),
                                };
 
-                               PendingHTLCStatus::Forward(PendingForwardHTLCInfo {
-                                       onion_packet: Some(outgoing_packet),
+                               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 { .. } => {
+                                               return_err!("Final Node OnionHopData provided for us as an intermediary node", 0x4000 | 22, &[0;0]);
+                                       },
+                               };
+
+                               PendingHTLCStatus::Forward(PendingHTLCInfo {
+                                       type_data: PendingForwardReceiveHTLCInfo::Forward {
+                                               onion_packet: outgoing_packet,
+                                               short_channel_id: short_channel_id,
+                                       },
                                        payment_hash: msg.payment_hash.clone(),
-                                       short_channel_id: next_hop_data.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,
@@ -1006,8 +1043,11 @@ impl<ChanSigner: ChannelKeys, M: Deref> ChannelManager<ChanSigner, M> where M::T
                        };
 
                channel_state = Some(self.channel_state.lock().unwrap());
-               if let &PendingHTLCStatus::Forward(PendingForwardHTLCInfo { 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 type_data, ref amt_to_forward, ref outgoing_cltv_value, .. }) = &pending_forward_info {
+                       // If short_channel_id is 0 here, we'll reject them in the body here (which is
+                       // important as various things later assume we are a ::Receive if short_channel_id is
+                       // non-0.
+                       if let &PendingForwardReceiveHTLCInfo::Forward { ref short_channel_id, .. } = type_data {
                                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
@@ -1143,6 +1183,9 @@ impl<ChanSigner: ChannelKeys, M: Deref> ChannelManager<ChanSigner, M> where M::T
                let onion_keys = secp_call!(onion_utils::construct_onion_keys(&self.secp_ctx, &route, &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)?;
+               if onion_utils::route_size_insane(&onion_payloads) {
+                       return Err(APIError::RouteError{err: "Route had too large size once"});
+               }
                let onion_packet = onion_utils::construct_onion_packet(onion_payloads, onion_keys, prng_seed, &payment_hash);
 
                let _ = self.total_consistency_lock.read().unwrap();
@@ -1291,6 +1334,37 @@ impl<ChanSigner: ChannelKeys, M: Deref> ChannelManager<ChanSigner, M> where M::T
                })
        }
 
+       /// Generates a signed node_announcement from the given arguments and creates a
+       /// BroadcastNodeAnnouncement event.
+       ///
+       /// RGB is a node "color" and alias a printable human-readable string to describe this node to
+       /// humans. They carry no in-protocol meaning.
+       ///
+       /// addresses represent the set (possibly empty) of socket addresses on which this node accepts
+       /// incoming connections.
+       pub fn broadcast_node_announcement(&self, rgb: [u8; 3], alias: [u8; 32], addresses: msgs::NetAddressSet) {
+               let _ = self.total_consistency_lock.read().unwrap();
+
+               let announcement = msgs::UnsignedNodeAnnouncement {
+                       features: NodeFeatures::supported(),
+                       timestamp: self.last_node_announcement_serial.fetch_add(1, Ordering::AcqRel) as u32,
+                       node_id: self.get_our_node_id(),
+                       rgb, alias,
+                       addresses: addresses.to_vec(),
+                       excess_address_data: Vec::new(),
+                       excess_data: Vec::new(),
+               };
+               let msghash = hash_to_message!(&Sha256dHash::hash(&announcement.encode()[..])[..]);
+
+               let mut channel_state = self.channel_state.lock().unwrap();
+               channel_state.pending_msg_events.push(events::MessageSendEvent::BroadcastNodeAnnouncement {
+                       msg: msgs::NodeAnnouncement {
+                               signature: self.secp_ctx.sign(&msghash, &self.our_network_key),
+                               contents: announcement
+                       },
+               });
+       }
+
        /// Processes HTLCs which are pending waiting on random forward delay.
        ///
        /// Should only really ever be called in response to a PendingHTLCsForwardable event.
@@ -1337,22 +1411,25 @@ impl<ChanSigner: ChannelKeys, M: Deref> ChannelManager<ChanSigner, M> where M::T
                                                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 {
+                                                                               type_data: PendingForwardReceiveHTLCInfo::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, 0x1000 | 7, Some(chan_update)));
                                                                                        continue;
                                                                                },
                                                                                Ok(update_add) => {
@@ -1371,6 +1448,9 @@ impl<ChanSigner: ChannelKeys, M: Deref> ChannelManager<ChanSigner, M> where M::T
                                                                                }
                                                                        }
                                                                },
+                                                               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) {
@@ -1450,21 +1530,26 @@ impl<ChanSigner: ChannelKeys, M: Deref> ChannelManager<ChanSigner, M> where M::T
                                } else {
                                        for forward_info in pending_forwards.drain(..) {
                                                match forward_info {
-                                                       HTLCForwardInfo::AddHTLC { prev_short_channel_id, prev_htlc_id, forward_info } => {
+                                                       HTLCForwardInfo::AddHTLC { prev_short_channel_id, prev_htlc_id, forward_info: PendingHTLCInfo {
+                                                                       type_data: PendingForwardReceiveHTLCInfo::Receive { },
+                                                                       incoming_shared_secret, payment_hash, amt_to_forward, .. }, } => {
                                                                let prev_hop_data = 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)]); },
+                                                               match channel_state.claimable_htlcs.entry(payment_hash) {
+                                                                       hash_map::Entry::Occupied(mut entry) => entry.get_mut().push((amt_to_forward, prev_hop_data)),
+                                                                       hash_map::Entry::Vacant(entry) => { entry.insert(vec![(amt_to_forward, prev_hop_data)]); },
                                                                };
                                                                new_events.push(events::Event::PaymentReceived {
-                                                                       payment_hash: forward_info.payment_hash,
-                                                                       amt: forward_info.amt_to_forward,
+                                                                       payment_hash: payment_hash,
+                                                                       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");
                                                        }
@@ -2125,7 +2210,7 @@ impl<ChanSigner: ChannelKeys, M: Deref> ChannelManager<ChanSigner, M> where M::T
                                        // If the update_add is completely bogus, the call will Err and we will close,
                                        // but if we've sent a shutdown and they haven't acknowledged it yet, we just
                                        // want to reject the new HTLC and fail it backwards instead of forwarding.
-                                       if let PendingHTLCStatus::Forward(PendingForwardHTLCInfo { incoming_shared_secret, .. }) = pending_forward_info {
+                                       if let PendingHTLCStatus::Forward(PendingHTLCInfo { incoming_shared_secret, .. }) = pending_forward_info {
                                                let chan_update = self.get_channel_update(chan.get());
                                                pending_forward_info = PendingHTLCStatus::Fail(HTLCFailureMsg::Relay(msgs::UpdateFailHTLC {
                                                        channel_id: msg.channel_id,
@@ -2255,7 +2340,7 @@ impl<ChanSigner: ChannelKeys, M: Deref> ChannelManager<ChanSigner, M> where M::T
        }
 
        #[inline]
-       fn forward_htlcs(&self, per_source_pending_forwards: &mut [(u64, Vec<(PendingForwardHTLCInfo, u64)>)]) {
+       fn forward_htlcs(&self, per_source_pending_forwards: &mut [(u64, Vec<(PendingHTLCInfo, u64)>)]) {
                for &mut (prev_short_channel_id, ref mut pending_forwards) in per_source_pending_forwards {
                        let mut forward_event = None;
                        if !pending_forwards.is_empty() {
@@ -2264,7 +2349,10 @@ impl<ChanSigner: ChannelKeys, M: Deref> ChannelManager<ChanSigner, M> where M::T
                                        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.type_data {
+                                                       PendingForwardReceiveHTLCInfo::Forward { short_channel_id, .. } => short_channel_id,
+                                                       PendingForwardReceiveHTLCInfo::Receive { .. } => 0,
+                                       }) {
                                                hash_map::Entry::Occupied(mut entry) => {
                                                        entry.get_mut().push(HTLCForwardInfo::AddHTLC { prev_short_channel_id, prev_htlc_id, forward_info });
                                                },
@@ -2886,6 +2974,7 @@ impl<ChanSigner: ChannelKeys, M: Deref + Sync + Send> ChannelMessageHandler for
                                        &events::MessageSendEvent::SendShutdown { ref node_id, .. } => node_id != their_node_id,
                                        &events::MessageSendEvent::SendChannelReestablish { ref node_id, .. } => node_id != their_node_id,
                                        &events::MessageSendEvent::BroadcastChannelAnnouncement { .. } => true,
+                                       &events::MessageSendEvent::BroadcastNodeAnnouncement { .. } => true,
                                        &events::MessageSendEvent::BroadcastChannelUpdate { .. } => true,
                                        &events::MessageSendEvent::HandleError { ref node_id, .. } => node_id != their_node_id,
                                        &events::MessageSendEvent::PaymentFailureNetworkUpdate { .. } => true,
@@ -2966,25 +3055,39 @@ impl<ChanSigner: ChannelKeys, M: Deref + Sync + Send> ChannelMessageHandler for
 const SERIALIZATION_VERSION: u8 = 1;
 const MIN_SERIALIZATION_VERSION: u8 = 1;
 
-impl Writeable for PendingForwardHTLCInfo {
+impl Writeable for PendingHTLCInfo {
        fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
-               self.onion_packet.write(writer)?;
+               match &self.type_data {
+                       &PendingForwardReceiveHTLCInfo::Forward { ref onion_packet, ref short_channel_id } => {
+                               0u8.write(writer)?;
+                               onion_packet.write(writer)?;
+                               short_channel_id.write(writer)?;
+                       },
+                       &PendingForwardReceiveHTLCInfo::Receive { } => {
+                               1u8.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(())
        }
 }
 
-impl<R: ::std::io::Read> Readable<R> for PendingForwardHTLCInfo {
-       fn read(reader: &mut R) -> Result<PendingForwardHTLCInfo, DecodeError> {
-               Ok(PendingForwardHTLCInfo {
-                       onion_packet: Readable::read(reader)?,
+impl<R: ::std::io::Read> Readable<R> for PendingHTLCInfo {
+       fn read(reader: &mut R) -> Result<PendingHTLCInfo, DecodeError> {
+               Ok(PendingHTLCInfo {
+                       type_data: match Readable::read(reader)? {
+                               0u8 => PendingForwardReceiveHTLCInfo::Forward {
+                                       onion_packet: Readable::read(reader)?,
+                                       short_channel_id: Readable::read(reader)?,
+                               },
+                               1u8 => PendingForwardReceiveHTLCInfo::Receive { },
+                               _ => 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)?,
                })
@@ -3199,6 +3302,8 @@ impl<ChanSigner: ChannelKeys + Writeable, M: Deref> Writeable for ChannelManager
                        peer_state.latest_features.write(writer)?;
                }
 
+               (self.last_node_announcement_serial.load(Ordering::Acquire) as u32).write(writer)?;
+
                Ok(())
        }
 }
@@ -3342,6 +3447,8 @@ impl<'a, R : ::std::io::Read, ChanSigner: ChannelKeys + Readable<R>, M: Deref> R
                        per_peer_state.insert(peer_pubkey, Mutex::new(peer_state));
                }
 
+               let last_node_announcement_serial: u32 = Readable::read(reader)?;
+
                let channel_manager = ChannelManager {
                        genesis_hash,
                        fee_estimator: args.fee_estimator,
@@ -3361,6 +3468,8 @@ impl<'a, R : ::std::io::Read, ChanSigner: ChannelKeys + Readable<R>, M: Deref> R
                        }),
                        our_network_key: args.keys_manager.get_node_secret(),
 
+                       last_node_announcement_serial: AtomicUsize::new(last_node_announcement_serial as usize),
+
                        per_peer_state: RwLock::new(per_peer_state),
 
                        pending_events: Mutex::new(Vec::new()),