Clarify when height is the *current* vs a *confirmation* height
[rust-lightning] / lightning / src / ln / channelmanager.rs
index 8f98bc3f2a5e749c36f23b26c4f5c159552114e1..766b2394b7ad38e3566f56b72906f4efe96800b1 100644 (file)
@@ -64,7 +64,6 @@ use util::errors::APIError;
 use prelude::*;
 use core::{cmp, mem};
 use core::cell::RefCell;
-use std::collections::{HashMap, hash_map, HashSet};
 use std::io::{Cursor, Read};
 use std::sync::{Arc, Condvar, Mutex, MutexGuard, RwLock, RwLockReadGuard};
 use core::sync::atomic::{AtomicUsize, Ordering};
@@ -498,6 +497,7 @@ pub struct ChannelManager<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref,
 /// Typically, the block-specific parameters are derived from the best block hash for the network,
 /// as a newly constructed `ChannelManager` will not have created any channels yet. These parameters
 /// are not needed when deserializing a previously constructed `ChannelManager`.
+#[derive(Clone, Copy, PartialEq)]
 pub struct ChainParameters {
        /// The network for determining the `chain_hash` in Lightning messages.
        pub network: Network,
@@ -509,7 +509,7 @@ pub struct ChainParameters {
 }
 
 /// The best known block as identified by its hash and height.
-#[derive(Clone, Copy)]
+#[derive(Clone, Copy, PartialEq)]
 pub struct BestBlock {
        block_hash: BlockHash,
        height: u32,
@@ -626,7 +626,7 @@ pub const MIN_FINAL_CLTV_EXPIRY: u32 = HTLC_FAIL_BACK_BUFFER + 3;
 const CHECK_CLTV_EXPIRY_SANITY: u32 = MIN_CLTV_EXPIRY_DELTA as u32 - LATENCY_GRACE_PERIOD_BLOCKS - CLTV_CLAIM_BUFFER - ANTI_REORG_DELAY - LATENCY_GRACE_PERIOD_BLOCKS;
 
 // Check for ability of an attacker to make us fail on-chain by delaying an HTLC claim. See
-// ChannelMontior::would_broadcast_at_height for a description of why this is needed.
+// ChannelMonitor::should_broadcast_holder_commitment_txn for a description of why this is needed.
 #[deny(const_err)]
 #[allow(dead_code)]
 const CHECK_CLTV_EXPIRY_SANITY_2: u32 = MIN_CLTV_EXPIRY_DELTA as u32 - LATENCY_GRACE_PERIOD_BLOCKS - 2*CLTV_CLAIM_BUFFER;
@@ -776,7 +776,7 @@ macro_rules! convert_chan_err {
                                (false, MsgHandleErrInternal::from_chan_no_close(ChannelError::Ignore(msg), $channel_id.clone()))
                        },
                        ChannelError::Close(msg) => {
-                               log_trace!($self.logger, "Closing channel {} due to close-required error: {}", log_bytes!($channel_id[..]), msg);
+                               log_error!($self.logger, "Closing channel {} due to close-required error: {}", log_bytes!($channel_id[..]), msg);
                                if let Some(short_id) = $channel.get_short_channel_id() {
                                        $short_to_id.remove(&short_id);
                                }
@@ -1243,7 +1243,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
        #[inline]
        fn finish_force_close_channel(&self, shutdown_res: ShutdownResult) {
                let (monitor_update_option, mut failed_htlcs) = shutdown_res;
-               log_trace!(self.logger, "Finishing force-closure of channel {} HTLCs to fail", failed_htlcs.len());
+               log_debug!(self.logger, "Finishing force-closure of channel with {} HTLCs to fail", failed_htlcs.len());
                for htlc_source in failed_htlcs.drain(..) {
                        self.fail_htlc_backwards_internal(self.channel_state.lock().unwrap(), htlc_source.0, &htlc_source.1, HTLCFailReason::Reason { failure_code: 0x4000 | 8, data: Vec::new() });
                }
@@ -1274,7 +1274,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                return Err(APIError::ChannelUnavailable{err: "No such channel".to_owned()});
                        }
                };
-               log_trace!(self.logger, "Force-closing channel {}", log_bytes!(channel_id[..]));
+               log_error!(self.logger, "Force-closing channel {}", log_bytes!(channel_id[..]));
                self.finish_force_close_channel(chan.force_shutdown(true));
                if let Ok(update) = self.get_channel_update(&chan) {
                        let mut channel_state = self.channel_state.lock().unwrap();
@@ -1671,6 +1671,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                                        return Err(APIError::MonitorUpdateFailed);
                                                }
 
+                                               log_debug!(self.logger, "Sending payment along path resulted in a commitment_signed for channel {}", log_bytes!(chan.get().channel_id()));
                                                channel_state.pending_msg_events.push(events::MessageSendEvent::UpdateHTLCs {
                                                        node_id: path.first().unwrap().pubkey,
                                                        updates: msgs::CommitmentUpdate {
@@ -2060,7 +2061,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                                                                        onion_packet, ..
                                                                                }, incoming_shared_secret, payment_hash, amt_to_forward, outgoing_cltv_value },
                                                                                prev_funding_outpoint } => {
-                                                                       log_trace!(self.logger, "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);
+                                                                       log_trace!(self.logger, "Adding HTLC from short id {} with payment_hash {} to channel with short id {} after delay", prev_short_channel_id, log_bytes!(payment_hash.0), short_chan_id);
                                                                        let htlc_source = HTLCSource::PreviousHopData(HTLCPreviousHopData {
                                                                                short_channel_id: prev_short_channel_id,
                                                                                outpoint: prev_funding_outpoint,
@@ -2100,11 +2101,11 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                                                        panic!("short_channel_id != 0 should imply any pending_forward entries are of type Forward");
                                                                },
                                                                HTLCForwardInfo::FailHTLC { htlc_id, err_packet } => {
-                                                                       log_trace!(self.logger, "Failing HTLC back to channel with short id {} after delay", short_chan_id);
+                                                                       log_trace!(self.logger, "Failing HTLC back to channel with short id {} (backward HTLC ID {}) after delay", short_chan_id, htlc_id);
                                                                        match chan.get_mut().get_update_fail_htlc(htlc_id, err_packet, &self.logger) {
                                                                                Err(e) => {
                                                                                        if let ChannelError::Ignore(msg) = e {
-                                                                                               log_trace!(self.logger, "Failed to fail backwards to short_id {}: {}", short_chan_id, msg);
+                                                                                               log_trace!(self.logger, "Failed to fail HTLC with ID {} backwards to short_id {}: {}", htlc_id, short_chan_id, msg);
                                                                                        } else {
                                                                                                panic!("Stated return value requirements in get_update_fail_htlc() were not met");
                                                                                        }
@@ -2158,6 +2159,8 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                                                handle_errors.push((chan.get().get_counterparty_node_id(), handle_monitor_err!(self, e, channel_state, chan, RAACommitmentOrder::CommitmentFirst, false, true)));
                                                                continue;
                                                        }
+                                                       log_debug!(self.logger, "Forwarding HTLCs resulted in a commitment update with {} HTLCs added and {} HTLCs failed for channel {}",
+                                                               add_htlc_msgs.len(), fail_htlc_msgs.len(), log_bytes!(chan.get().channel_id()));
                                                        channel_state.pending_msg_events.push(events::MessageSendEvent::UpdateHTLCs {
                                                                node_id: chan.get().get_counterparty_node_id(),
                                                                updates: msgs::CommitmentUpdate {
@@ -2664,6 +2667,8 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                                }
                                        }
                                        if let Some((msg, commitment_signed)) = msgs {
+                                               log_debug!(self.logger, "Claiming funds for HTLC with preimage {} resulted in a commitment_signed for channel {}",
+                                                       log_bytes!(payment_preimage.0), log_bytes!(chan.get().channel_id()));
                                                channel_state.pending_msg_events.push(events::MessageSendEvent::UpdateHTLCs {
                                                        node_id: chan.get().get_counterparty_node_id(),
                                                        updates: msgs::CommitmentUpdate {
@@ -2927,7 +2932,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                if chan.get().get_counterparty_node_id() != *counterparty_node_id {
                                        return Err(MsgHandleErrInternal::send_err_msg_no_close("Got a message for a channel from the wrong node!".to_owned(), msg.channel_id));
                                }
-                               try_chan_entry!(self, chan.get_mut().funding_locked(&msg), channel_state, chan);
+                               try_chan_entry!(self, chan.get_mut().funding_locked(&msg, &self.logger), channel_state, chan);
                                if let Some(announcement_sigs) = self.get_announcement_sigs(chan.get()) {
                                        log_trace!(self.logger, "Sending announcement_signatures for {} in response to funding_locked", log_bytes!(chan.get().channel_id()));
                                        // If we see locking block before receiving remote funding_locked, we broadcast our
@@ -3354,8 +3359,13 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                match channel_state.by_id.entry(chan_id) {
                        hash_map::Entry::Occupied(mut chan) => {
                                if chan.get().get_counterparty_node_id() != *counterparty_node_id {
-                                       // TODO: see issue #153, need a consistent behavior on obnoxious behavior from random node
-                                       return Err(MsgHandleErrInternal::send_err_msg_no_close("Got a message for a channel from the wrong node!".to_owned(), chan_id));
+                                       if chan.get().should_announce() {
+                                               // If the announcement is about a channel of ours which is public, some
+                                               // other peer may simply be forwarding all its gossip to us. Don't provide
+                                               // a scary-looking error message and return Ok instead.
+                                               return Ok(());
+                                       }
+                                       return Err(MsgHandleErrInternal::send_err_msg_no_close("Got a channel_update for a channel from the wrong node - it shouldn't know about our private channels!".to_owned(), chan_id));
                                }
                                try_chan_entry!(self, chan.get_mut().channel_update(&msg), channel_state, chan);
                        },
@@ -3365,7 +3375,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
        }
 
        fn internal_channel_reestablish(&self, counterparty_node_id: &PublicKey, msg: &msgs::ChannelReestablish) -> Result<(), MsgHandleErrInternal> {
-               let (htlcs_failed_forward, chan_restoration_res) = {
+               let (htlcs_failed_forward, need_lnd_workaround, chan_restoration_res) = {
                        let mut channel_state_lock = self.channel_state.lock().unwrap();
                        let channel_state = &mut *channel_state_lock;
 
@@ -3386,13 +3396,19 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                                        msg,
                                                });
                                        }
-                                       (htlcs_failed_forward, handle_chan_restoration_locked!(self, channel_state_lock, channel_state, chan, revoke_and_ack, commitment_update, order, monitor_update_opt, Vec::new(), None, funding_locked))
+                                       let need_lnd_workaround = chan.get_mut().workaround_lnd_bug_4006.take();
+                                       (htlcs_failed_forward, need_lnd_workaround,
+                                               handle_chan_restoration_locked!(self, channel_state_lock, channel_state, chan, revoke_and_ack, commitment_update, order, monitor_update_opt, Vec::new(), None, funding_locked))
                                },
                                hash_map::Entry::Vacant(_) => return Err(MsgHandleErrInternal::send_err_msg_no_close("Failed to find corresponding channel".to_owned(), msg.channel_id))
                        }
                };
                post_handle_chan_restoration!(self, chan_restoration_res);
                self.fail_holding_cell_htlcs(htlcs_failed_forward, msg.channel_id);
+
+               if let Some(funding_locked_msg) = need_lnd_workaround {
+                       self.internal_funding_locked(counterparty_node_id, &funding_locked_msg)?;
+               }
                Ok(())
        }
 
@@ -3428,6 +3444,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> ChannelMana
                                                if let Err(_e) = self.chain_monitor.update_channel(chan.get().get_funding_txo().unwrap(), monitor_update) {
                                                        unimplemented!();
                                                }
+                                               log_debug!(self.logger, "Updating fee resulted in a commitment_signed for channel {}", log_bytes!(chan.get().channel_id()));
                                                channel_state.pending_msg_events.push(events::MessageSendEvent::UpdateHTLCs {
                                                        node_id: chan.get().get_counterparty_node_id(),
                                                        updates: msgs::CommitmentUpdate {
@@ -3804,7 +3821,7 @@ where
                        *best_block = BestBlock::new(header.prev_blockhash, new_height)
                }
 
-               self.do_chain_event(Some(new_height), |channel| channel.best_block_updated(new_height, header.time));
+               self.do_chain_event(Some(new_height), |channel| channel.best_block_updated(new_height, header.time, &self.logger));
        }
 }
 
@@ -3840,7 +3857,7 @@ where
 
                *self.best_block.write().unwrap() = BestBlock::new(block_hash, height);
 
-               self.do_chain_event(Some(height), |channel| channel.best_block_updated(height, header.time));
+               self.do_chain_event(Some(height), |channel| channel.best_block_updated(height, header.time, &self.logger));
 
                macro_rules! max_time {
                        ($timestamp: expr) => {
@@ -3882,7 +3899,7 @@ where
                self.do_chain_event(None, |channel| {
                        if let Some(funding_txo) = channel.get_funding_txo() {
                                if funding_txo.txid == *txid {
-                                       channel.funding_transaction_unconfirmed().map(|_| (None, Vec::new()))
+                                       channel.funding_transaction_unconfirmed(&self.logger).map(|_| (None, Vec::new()))
                                } else { Ok((None, Vec::new())) }
                        } else { Ok((None, Vec::new())) }
                });
@@ -4318,261 +4335,87 @@ impl PersistenceNotifier {
 const SERIALIZATION_VERSION: u8 = 1;
 const MIN_SERIALIZATION_VERSION: u8 = 1;
 
-impl Writeable for PendingHTLCRouting {
-       fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
-               match &self {
-                       &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, ref incoming_cltv_expiry } => {
-                               1u8.write(writer)?;
-                               payment_data.payment_secret.write(writer)?;
-                               payment_data.total_msat.write(writer)?;
-                               incoming_cltv_expiry.write(writer)?;
-                       },
-               }
-               Ok(())
-       }
-}
-
-impl Readable for PendingHTLCRouting {
-       fn read<R: ::std::io::Read>(reader: &mut R) -> Result<PendingHTLCRouting, DecodeError> {
-               match Readable::read(reader)? {
-                       0u8 => Ok(PendingHTLCRouting::Forward {
-                               onion_packet: Readable::read(reader)?,
-                               short_channel_id: Readable::read(reader)?,
-                       }),
-                       1u8 => Ok(PendingHTLCRouting::Receive {
-                               payment_data: msgs::FinalOnionHopData {
-                                       payment_secret: Readable::read(reader)?,
-                                       total_msat: Readable::read(reader)?,
-                               },
-                               incoming_cltv_expiry: Readable::read(reader)?,
-                       }),
-                       _ => Err(DecodeError::InvalidValue),
-               }
+impl_writeable_tlv_based_enum!(PendingHTLCRouting,
+       (0, Forward) => {
+               (0, onion_packet, required),
+               (2, short_channel_id, required),
+       },
+       (1, Receive) => {
+               (0, payment_data, required),
+               (2, incoming_cltv_expiry, required),
        }
-}
+;);
 
 impl_writeable_tlv_based!(PendingHTLCInfo, {
-       (0, routing),
-       (2, incoming_shared_secret),
-       (4, payment_hash),
-       (6, amt_to_forward),
-       (8, outgoing_cltv_value)
-}, {}, {});
-
-impl Writeable for HTLCFailureMsg {
-       fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
-               match self {
-                       &HTLCFailureMsg::Relay(ref fail_msg) => {
-                               0u8.write(writer)?;
-                               fail_msg.write(writer)?;
-                       },
-                       &HTLCFailureMsg::Malformed(ref fail_msg) => {
-                               1u8.write(writer)?;
-                               fail_msg.write(writer)?;
-                       }
-               }
-               Ok(())
-       }
-}
-
-impl Readable for HTLCFailureMsg {
-       fn read<R: ::std::io::Read>(reader: &mut R) -> Result<HTLCFailureMsg, DecodeError> {
-               match <u8 as Readable>::read(reader)? {
-                       0 => Ok(HTLCFailureMsg::Relay(Readable::read(reader)?)),
-                       1 => Ok(HTLCFailureMsg::Malformed(Readable::read(reader)?)),
-                       _ => Err(DecodeError::InvalidValue),
-               }
-       }
-}
-
-impl Writeable for PendingHTLCStatus {
-       fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
-               match self {
-                       &PendingHTLCStatus::Forward(ref forward_info) => {
-                               0u8.write(writer)?;
-                               forward_info.write(writer)?;
-                       },
-                       &PendingHTLCStatus::Fail(ref fail_msg) => {
-                               1u8.write(writer)?;
-                               fail_msg.write(writer)?;
-                       }
-               }
-               Ok(())
-       }
-}
-
-impl Readable for PendingHTLCStatus {
-       fn read<R: ::std::io::Read>(reader: &mut R) -> Result<PendingHTLCStatus, DecodeError> {
-               match <u8 as Readable>::read(reader)? {
-                       0 => Ok(PendingHTLCStatus::Forward(Readable::read(reader)?)),
-                       1 => Ok(PendingHTLCStatus::Fail(Readable::read(reader)?)),
-                       _ => Err(DecodeError::InvalidValue),
-               }
-       }
-}
+       (0, routing, required),
+       (2, incoming_shared_secret, required),
+       (4, payment_hash, required),
+       (6, amt_to_forward, required),
+       (8, outgoing_cltv_value, required)
+});
+
+impl_writeable_tlv_based_enum!(HTLCFailureMsg, ;
+       (0, Relay),
+       (1, Malformed),
+);
+impl_writeable_tlv_based_enum!(PendingHTLCStatus, ;
+       (0, Forward),
+       (1, Fail),
+);
 
 impl_writeable_tlv_based!(HTLCPreviousHopData, {
-       (0, short_channel_id),
-       (2, outpoint),
-       (4, htlc_id),
-       (6, incoming_packet_shared_secret)
-}, {}, {});
-
-impl Writeable for ClaimableHTLC {
-       fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
-               write_tlv_fields!(writer, {
-                       (0, self.prev_hop),
-                       (2, self.value),
-                       (4, self.payment_data.payment_secret),
-                       (6, self.payment_data.total_msat),
-                       (8, self.cltv_expiry)
-               }, {});
-               Ok(())
-       }
-}
-
-impl Readable for ClaimableHTLC {
-       fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
-               let mut prev_hop = HTLCPreviousHopData {
-                       short_channel_id: 0, htlc_id: 0,
-                       incoming_packet_shared_secret: [0; 32],
-                       outpoint: OutPoint::null(),
-               };
-               let mut value = 0;
-               let mut payment_secret = PaymentSecret([0; 32]);
-               let mut total_msat = 0;
-               let mut cltv_expiry = 0;
-               read_tlv_fields!(reader, {
-                       (0, prev_hop),
-                       (2, value),
-                       (4, payment_secret),
-                       (6, total_msat),
-                       (8, cltv_expiry)
-               }, {});
-               Ok(ClaimableHTLC {
-                       prev_hop,
-                       value,
-                       payment_data: msgs::FinalOnionHopData {
-                               payment_secret,
-                               total_msat,
-                       },
-                       cltv_expiry,
-               })
-       }
-}
-
-impl Writeable for HTLCSource {
-       fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
-               match self {
-                       &HTLCSource::PreviousHopData(ref hop_data) => {
-                               0u8.write(writer)?;
-                               hop_data.write(writer)?;
-                       },
-                       &HTLCSource::OutboundRoute { ref path, ref session_priv, ref first_hop_htlc_msat } => {
-                               1u8.write(writer)?;
-                               path.write(writer)?;
-                               session_priv.write(writer)?;
-                               first_hop_htlc_msat.write(writer)?;
-                       }
-               }
-               Ok(())
-       }
-}
-
-impl Readable for HTLCSource {
-       fn read<R: ::std::io::Read>(reader: &mut R) -> Result<HTLCSource, DecodeError> {
-               match <u8 as Readable>::read(reader)? {
-                       0 => Ok(HTLCSource::PreviousHopData(Readable::read(reader)?)),
-                       1 => Ok(HTLCSource::OutboundRoute {
-                               path: Readable::read(reader)?,
-                               session_priv: Readable::read(reader)?,
-                               first_hop_htlc_msat: Readable::read(reader)?,
-                       }),
-                       _ => Err(DecodeError::InvalidValue),
-               }
-       }
-}
-
-impl Writeable for HTLCFailReason {
-       fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
-               match self {
-                       &HTLCFailReason::LightningError { ref err } => {
-                               0u8.write(writer)?;
-                               err.write(writer)?;
-                       },
-                       &HTLCFailReason::Reason { ref failure_code, ref data } => {
-                               1u8.write(writer)?;
-                               failure_code.write(writer)?;
-                               data.write(writer)?;
-                       }
-               }
-               Ok(())
-       }
-}
-
-impl Readable for HTLCFailReason {
-       fn read<R: ::std::io::Read>(reader: &mut R) -> Result<HTLCFailReason, DecodeError> {
-               match <u8 as Readable>::read(reader)? {
-                       0 => Ok(HTLCFailReason::LightningError { err: Readable::read(reader)? }),
-                       1 => Ok(HTLCFailReason::Reason {
-                               failure_code: Readable::read(reader)?,
-                               data: Readable::read(reader)?,
-                       }),
-                       _ => Err(DecodeError::InvalidValue),
-               }
-       }
-}
-
-impl Writeable for HTLCForwardInfo {
-       fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
-               match self {
-                       &HTLCForwardInfo::AddHTLC { ref prev_short_channel_id, ref prev_funding_outpoint, ref prev_htlc_id, ref forward_info } => {
-                               0u8.write(writer)?;
-                               prev_short_channel_id.write(writer)?;
-                               prev_funding_outpoint.write(writer)?;
-                               prev_htlc_id.write(writer)?;
-                               forward_info.write(writer)?;
-                       },
-                       &HTLCForwardInfo::FailHTLC { ref htlc_id, ref err_packet } => {
-                               1u8.write(writer)?;
-                               htlc_id.write(writer)?;
-                               err_packet.write(writer)?;
-                       },
-               }
-               Ok(())
-       }
-}
-
-impl Readable for HTLCForwardInfo {
-       fn read<R: ::std::io::Read>(reader: &mut R) -> Result<HTLCForwardInfo, DecodeError> {
-               match <u8 as Readable>::read(reader)? {
-                       0 => Ok(HTLCForwardInfo::AddHTLC {
-                               prev_short_channel_id: Readable::read(reader)?,
-                               prev_funding_outpoint: Readable::read(reader)?,
-                               prev_htlc_id: Readable::read(reader)?,
-                               forward_info: Readable::read(reader)?,
-                       }),
-                       1 => Ok(HTLCForwardInfo::FailHTLC {
-                               htlc_id: Readable::read(reader)?,
-                               err_packet: Readable::read(reader)?,
-                       }),
-                       _ => Err(DecodeError::InvalidValue),
-               }
-       }
-}
+       (0, short_channel_id, required),
+       (2, outpoint, required),
+       (4, htlc_id, required),
+       (6, incoming_packet_shared_secret, required)
+});
+
+impl_writeable_tlv_based!(ClaimableHTLC, {
+       (0, prev_hop, required),
+       (2, value, required),
+       (4, payment_data, required),
+       (6, cltv_expiry, required),
+});
+
+impl_writeable_tlv_based_enum!(HTLCSource,
+       (0, OutboundRoute) => {
+               (0, session_priv, required),
+               (2, first_hop_htlc_msat, required),
+               (4, path, vec_type),
+       }, ;
+       (1, PreviousHopData)
+);
+
+impl_writeable_tlv_based_enum!(HTLCFailReason,
+       (0, LightningError) => {
+               (0, err, required),
+       },
+       (1, Reason) => {
+               (0, failure_code, required),
+               (2, data, vec_type),
+       },
+;);
+
+impl_writeable_tlv_based_enum!(HTLCForwardInfo,
+       (0, AddHTLC) => {
+               (0, forward_info, required),
+               (2, prev_short_channel_id, required),
+               (4, prev_htlc_id, required),
+               (6, prev_funding_outpoint, required),
+       },
+       (1, FailHTLC) => {
+               (0, htlc_id, required),
+               (2, err_packet, required),
+       },
+;);
 
 impl_writeable_tlv_based!(PendingInboundPayment, {
-       (0, payment_secret),
-       (2, expiry_time),
-       (4, user_payment_id),
-       (6, payment_preimage),
-       (8, min_value_msat),
-}, {}, {});
+       (0, payment_secret, required),
+       (2, expiry_time, required),
+       (4, user_payment_id, required),
+       (6, payment_preimage, required),
+       (8, min_value_msat, required),
+});
 
 impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> Writeable for ChannelManager<Signer, M, T, K, F, L>
        where M::Target: chain::Watch<Signer>,
@@ -4667,7 +4510,7 @@ impl<Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref> Writeable f
                        session_priv.write(writer)?;
                }
 
-               write_tlv_fields!(writer, {}, {});
+               write_tlv_fields!(writer, {});
 
                Ok(())
        }
@@ -4814,6 +4657,11 @@ impl<'a, Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
                                                channel.get_cur_counterparty_commitment_transaction_number() < monitor.get_cur_counterparty_commitment_number() ||
                                                channel.get_latest_monitor_update_id() > monitor.get_latest_update_id() {
                                        // If the channel is ahead of the monitor, return InvalidValue:
+                                       log_error!(args.logger, "A ChannelMonitor is stale compared to the current ChannelManager! This indicates a potentially-critical violation of the chain::Watch API!");
+                                       log_error!(args.logger, " The ChannelMonitor for channel {} is at update_id {} but the ChannelManager is at update_id {}.",
+                                               log_bytes!(channel.channel_id()), monitor.get_latest_update_id(), channel.get_latest_monitor_update_id());
+                                       log_error!(args.logger, " The chain::Watch API *requires* that monitors are persisted durably before returning,");
+                                       log_error!(args.logger, " client applications must ensure that ChannelMonitor data is always available and the latest to avoid funds loss!");
                                        return Err(DecodeError::InvalidValue);
                                } else if channel.get_cur_holder_commitment_transaction_number() > monitor.get_cur_holder_commitment_number() ||
                                                channel.get_revoked_counterparty_commitment_transaction_number() > monitor.get_min_seen_secret() ||
@@ -4830,6 +4678,9 @@ impl<'a, Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
                                        by_id.insert(channel.channel_id(), channel);
                                }
                        } else {
+                               log_error!(args.logger, "Missing ChannelMonitor for channel {} needed by ChannelManager.", log_bytes!(channel.channel_id()));
+                               log_error!(args.logger, " The chain::Watch API *requires* that monitors are persisted durably before returning,");
+                               log_error!(args.logger, " client applications must ensure that ChannelMonitor data is always available and the latest to avoid funds loss!");
                                return Err(DecodeError::InvalidValue);
                        }
                }
@@ -4912,7 +4763,7 @@ impl<'a, Signer: Sign, M: Deref, T: Deref, K: Deref, F: Deref, L: Deref>
                        }
                }
 
-               read_tlv_fields!(reader, {}, {});
+               read_tlv_fields!(reader, {});
 
                let mut secp_ctx = Secp256k1::new();
                secp_ctx.seeded_randomize(&args.keys_manager.get_secure_random_bytes());